Materials Today Bio

Developing wound dressings that support healing and allow real-time monitoring is a key priority in modern wound care. In this study, we designed a curcumin-loaded carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA) composite dressing with integrated pH-responsive colorimetric sensing. The films were made by solution blending and freeze-drying. They formed porous, absorbent structures that quickly absorbed fluid and managed wound exudates effectively. Curcumin served as both a therapeutic agent--delivering antioxidant, anti-inflammatory, and antibacterial effects--and a natural colorimetric indicator through its keto-enol tautomerism, enabling reversible pH-dependent transitions visible to the naked eye. UV-Vis spectroscopy confirmed absorbance shifts under acidic and alkaline conditions. It also showed that curcumin remained [~]80% stable after 14 days in the polymer matrix FTIR and SEM confirmed successful incorporation and uniform distribution of curcumin within the polymer network. Cytotoxicity assays demonstrated excellent biocompatibility, while disc diffusion and MIC assays revealed significant antibacterial activity of the curcumin-loaded films against Pseudomonas aeruginosa, confirming their potential to reduce bacterial growth. Smartphone-based RGB analysis showed a strong correlation with pH (R2 {approx} 0.99), highlighting the feasibility of low-cost digital wound monitoring. Mechanical testing indicated sufficient tensile strength and flexibility for practical wound application. Quantitative antibacterial data (inhibition zone diameter and MIC) supported strong antimicrobial performance. The primary objective of this study was to develop a multifunctional wound dressing capable of both protecting and monitoring wounds in real-time. The proposed system is specifically designed for chronic and infected wounds where pH imbalance delays healing. In addition to antimicrobial activity, the fabricated films demonstrated desirable swelling capacity and sustained curcumin release, further highlighting the practical applicability of the dressing in wound care. Cost- benefit analysis demonstrated clear economic advantages over commercial gauze-based and hydrocolloid dressings. The fabrication method is compatible with industrial scale-up, although process optimization is required. Overall, the curcumin-loaded CMC/PVA dressing provides a multifunctional platform that combines biocompatibility, antibacterial activity, pH-responsive biosensing, and cost-effectiveness for next-generation wound care. Future studies will investigate in vivo performance, long-term stability, and clinical translation potential to validate its effectiveness in real-world conditions. Overall, the curcumin-loaded CMC/PVA dressing provides a multifunctional platform that combines biocompatibility, antibacterial activity, pH-responsive biosensing, mechanical stability, and cost-effectiveness for next-generation wound care. Future studies will investigate in vivo performance, long-term stability, and clinical translation potential.

Controlled delivery of growth factors and viable cells remains a significant challenge in bone tissue engineering. In this study, a 3D-printed hydrogel scaffold system was developed for the co-delivery of bone morphogenetic protein-9 (BMP-9) and preosteoblasts to enhance bone regeneration. The system consisted of a 3D-printed base scaffold containing BMP-9-coated calcium sulfate (CaS) microparticles and a photocurable hydrogel coating layer encapsulating viable cells. The scaffold design exploited electrostatic interactions between BMP-9 and gelatin matrices by incorporating gelatin type B in the base scaffold and gelatin type A in the coating layer. Differences in the isoelectric points of these gelatin types were utilized to regulate protein binding and release. Release studies demonstrated that CaS microparticles alone exhibited rapid burst release, with nearly 80% of BMP-9 released within 24 h. Encapsulation of BMP-9 coated CaS particles in the 3D-printed scaffolds reduced the release rate, while the addition of the coating layer significantly improved sustained release, limiting BMP-9 release to approximately 50-60% by day 5. Bioactivity studies showed enhanced cell attachment in BMP-9 containing scaffolds compared with controls. Live/Dead cytotoxicity assays demonstrated high cell viability (>80%) within the coating layer over the culture period, confirming that the encapsulation and photocuring processes did not adversely affect cell survival. Cell proliferation and differentiation were further evaluated using WST-1 and alkaline phosphatase assays. The results demonstrate that electrostatic interactions governed by gelatin type selection can regulate BMP-9 release while maintaining high cell viability, providing a promising platform for growth factors and cell delivery in bone tissue engineering.

Intravasation is the process by which cancer cells breach the physical boundaries of a primary tumor and enter blood or lymphatic vessels. In this work, MCF-7 breast cancer cells were cultured within polymer-based microcapsules (here referred to as artificial microtumors) to investigate the transcriptomic and morpho-mechanical changes occurring in cancer cells during their release from these matrices, mimicking in vitro the process of intravasation. Our results show that even confined and released cancer cells share approximately 95% of their global transcriptomic profiles, intravasation-like cells exhibited marked differences in the expression of pathogenic hallmarks, including pathways associated with cell proliferation, immunosurveillance, and dormancy. Notably, a clear upregulation of YAP/TAZ signaling was observed in released cells, a result further supported by single-cell traction force microscopy assays, demonstrating that those cells exhibit higher biomechanical activity compared to cells located within artificial microtumors or those cultured on conventional 2D flasks, as shown for intravasated cells in vivo. To further enrich our investigation, the mechanotranscriptomic activity of MCF-7 cells was compared with suspended spheroids cultured on non-adherent surfaces (i.e., agarose hydrogels). Our results show that released cells displayed increased biomechanical activity and elevated expression of malignant markers, indicating that mechanical stress, beyond cell-cell contact alone, is required to trigger malignant responses. These observations were further supported by co-culture studies of MCF-7 cells with human fibroblasts and endothelial cells, which showed reduced proliferative and invasive capacities under confinement. Overall, our findings demonstrate that shifts in mechanical and metabolic stress, as experienced during intravasation, act as critical stimuli driving mechanotranscriptomic programs associated with cancer progression.

Nanomaterials have been proposed as drug delivery vehicles to enhance targeting and efficiency of traditional and novel therapeutics and have subsequently been studied for potential ecotoxicity. Previous studies have identified size, surface charge, and volume exclusion as factors that influence nanomaterial diffusion and retention. However, there is little accepted or successful quantification of how these parameters influence nanomaterial penetration relative to biological adaptation and biological response. Part of the challenge is the response of living biological interfaces to many of these nanomaterial delivery vehicles and nanosized drugs. This study aimed to emulate key physicochemical barriers to diffusion found in living biomaterials by developing a tunable, synthetic hydrogel. Through the controlled exposure of 150 kDa and 2 MDa nanodextrans with neutral and negative surface charge, we evaluated the systems ability to emulate three core physicochemical features often implicated in biofilm-associated transport resistance: size exclusion, charge interactions, and volume exclusion. We demonstrated a 30% statistically significant decrease in partition coefficients for 2 MDa nanodextran from 150 kDa nanodextran, confirming the ability of the nanocellulose-based microcaps to mimic the permeability of hydrated biomaterial matrices. These findings reflect patterns observed in, for example, living biofilm studies, where size-based diffusion hinderance is commonly reported, but charge-based interaction and volume exclusion are more context-dependent. This controllable system can be coupled with in silico modeling to understand interfacial transport phenomena for nanomaterial-biomaterial interactions. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=91 SRC="FIGDIR/small/703274v1_ufig1.gif" ALT="Figure 1"> View larger version (21K): org.highwire.dtl.DTLVardef@13c1a34org.highwire.dtl.DTLVardef@dc6c5borg.highwire.dtl.DTLVardef@14dcbd4org.highwire.dtl.DTLVardef@80f70c_HPS_FORMAT_FIGEXP M_FIG C_FIG

Alginate hydrogels are widely used for biocompatible encapsulation due to their low cost, mild gelation conditions, and scalability; however, their limited mechanical strength and poor chemical stability under physiological conditions restrict their utility for oral delivery applications. In particular, the development of robust alginate formulations capable of surviving gastrointestinal salt and pH exposures is critical for advancing encapsulated microbial therapeutics for chronic kidney disease (CKD). In this study, we investigated the incorporation of ferric iron into calcium alginate networks as a strategy to enhance gel stability while maintaining biocompatibility. Using a three-ion competition approach, we achieved controlled introduction of ferric ions into calcium alginate gels without significantly altering bulk mechanical properties relative to standard calcium alginate. Although the initial ferric-containing gels displayed comparable modulus and structure, post-treatment with chitosan under mildly acidic conditions produced a dramatic increase in gel stability in physiological salt concentrations across both acidic and neutral pH environments. Ferric-containing gels formed at pH 4.6 absorbed negligible chitosan, in contrast to iron-free alginate gels, which incorporated substantial chitosan under identical conditions. These results support the formation of a thin, dense interfacial complex between chitosan, ferric ions, and alginate at the gel surface, which reinforces the matrix and inhibits dissolution. The resulting hybrid ferric-calcium alginate formulation enabled the production of sub-millimeter beads capable of encapsulating live Thauera aminoaromatica while preserving anaerobic p-cresol degradation activity at 37 {degrees}C using nitrate as an electron acceptor. Collectively, these findings establish ferric-modified alginate hydrogels as a promising, scalable platform for stable oral delivery of encapsulated microbial therapeutics.

Colonisation of plastic surfaces by microbial biofilms offers a promising starting point for engineering efficient biodegradation systems. However, most studies to date focus on characterisation or prevention of biofilms on plastics in diverse environments and the potential biotechnological application for these systems has been underexplored. To address this, we report the efficient adhesion of Escherichia coli cells to a range of plastic surfaces through overexpression of two key determinants of bacterial biofilm formation; curli and Antigen 43 (Ag43). A general trend of higher total biomass was observed from curli-mediated adhesion, but more uniform adhesion from Ag43 overexpression. We further demonstrate application of this technology through inducible adhesion of E. coli to polyethylene terephthalate (PET) surfaces and concurrent secretion of the PET depolymerase PHL7. Co-overexpression of curli fibres and secreted PHL7 resulted in 5.6-fold increase in terephthalic acid release in comparison to the non-adherent control. These methods offer a general approach to programmable adhesion of genetically tractable cells to plastic surfaces and concurrent secretion of degradative enzymes, and are anticipated to be broadly applicable across the field of plastic bioremediation technologies.

Polysaccharides are often used to mimic physiological environments such as for cancer research models. However, established polysaccharides can display limited long-term stability and high batch-to-batch variability. To overcome this, biomanufactured polysaccharides are increasingly utilized in biomaterials. Here, we produced and characterized Rhodotorula toruloides yeast exopolysaccharides (EPS) and used it to engineer hydrogel for culturing cancer cells. Yeast fermentation of glucose, mannose, and xylose yielded varying EPS amounts (1.68, 1.44, and 0.48 g/L, respectively) with similar compositions, suggesting a common biosynthetic pathway. The glucose-derived EPS characterization identified multiple linkage types and three molecular weight fractions (1.75, 30.0, and 1000 kDa), and its solutions exhibited Newtonian behavior, indicating minimal chain-chain interactions. Solubilizing this polydisperse EPS with polyethylene glycol diacrylate and UV-crosslinking it enabled the engineering of semi-interpenetrating polymer network hydrogel that efficiently embedded cancer spheroids. Our study introduces an integrated biomanufacturing strategy to generate stable and consistent biomaterials, applicable for tissue engineering. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=104 SRC="FIGDIR/small/703759v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@110d079org.highwire.dtl.DTLVardef@e6e390org.highwire.dtl.DTLVardef@662540org.highwire.dtl.DTLVardef@17afd5_HPS_FORMAT_FIGEXP M_FIG C_FIG

Biomimetic tubular scaffolds hold great promise for tackling unmet clinical needs thanks to their biocompatibility and recapitulation of cellular microenvironments, conferring the ability to promote regeneration. Potential applications include small-diameter vascular implants and grafts for airway repair, for which no viable off-the-shelf solutions currently exist. The tubular materials (4 and 8 mm internal and external diameters) presented here consist purely of type I collagen, contain no chemical crosslinkers, and reproduce the multi-scale architecture of the native tissue including the presence of collagen fibrils. A novel two-step protocol provides materials with distinct concentric layers. A porous external structure, obtained by means of ice templating combined with collagen topotactic fibrillogenesis, favours oriented cell colonization. A smooth and much less porous internal layer provides mechanical and water-tightness properties relevant for in vivo implantation and promotes the formation of an endothelial monolayer under both static and flow conditions. The compliance of the double-layered materials under physiological pressure is close to that of piglet carotid arteries. The materials are also determined to be sufficiently flexible to provide the ability to perform ex vivo anastomosis with bronchi, although the relatively low value of suture retention strength remains a limitation for in vivo suturing.

1.Liquid crystal polymer (LCP) is commonly used in the electronics industry due to its favorable dielectric, thermal, and insulative properties. It has recently gained popularity in the medical field for these same reasons, as well as its biocompatibility, moisture barrier properties, and ability to be microfabricated into thin film flexible circuits or flex PCBs. While polymers such as polyimide and Parylene C remain more common for electronics encapsulation and flexible circuit fabrication due to their relatively lower barriers to adoption and history of use, LCPs superior moisture barrier performance and low risk of delamination make it a promising material for chronic use in medical devices. In this work, the moisture barrier properties of LCP are evaluated using in vitro accelerated aging over 59-61 weeks at 65-68 {degrees}C, corresponding to an equivalent implanted lifetime of 8.1 and 9.4 years at 37 {degrees}C for each of two sample groups: LCP as an electronics encapsulant and as a flexible circuit substrate. In the encapsulation group, relative humidity inside an encapsulation pocket was monitored over time with no noticeable change in humidity throughout the measurement period. In the flexible circuit group, impedance of laminated interdigitated electrodes was monitored over time, with an average decrease to 44% of the initial impedance value across all successful samples due to the moisture absorption of the LCP, which has remained stable for the latter half of testing. In both groups, no delamination was observed. These findings demonstrate that LCP is a viable moisture barrier for electronics in implanted medical devices for an estimated equivalent lifetime of at least 8.1 years.

APOSECTM, a complex mixture of secreted proteins, lipids, and extracellular vesicles from stressed peripheral blood monocytes, is currently in clinical trials for the treatment of chronic, poorly healing wounds. When applied to open wounds, 1 mL reconstituted APOSECTM lyophilisate is syringe-mixed with 3 g sterile hydrogel prior to administration. This study investigates the pharmaceutical performance of this novel administration system. A gel formulation (APOgel) was developed for terminal sterilisation in pre-filled syringes with post-sterilisation viscosity ([~]325-350{square}Pa*s at 1{square}s-1) comparable to a commercial benchmark gel. Syringe mixing of APOgel with a liquid APOSECTM surrogate (3:1) reduced viscosity by [~]67% but was highly reproducible across different operators (CV < 6%). Administration of three sequential dose units of the mixture from the syringe revealed an [~]20% higher content of active ingredients in the first and final dispensed compared to the middle unit, indicating non-uniform mixing in the closed syringe system. In vitro release studies over 72{square}h showed a 32% and 48% higher release of a small molecule marker and total proteins from the sterile APOgel compared to the benchmark gel as well as more pronounced gel swelling. However, efficacy studies in a murine wound healing model showed no significant difference between APOgel and the benchmark. These findings indicate that terminal sterilisation of gels for topical applications may provide benefits for more rapid release of active agents but syringe mixing of gels and a liquid requires optimisation to ensure uniform drug distribution. HighlightsO_LIAn autoclavable hydrogel for APOSECTM delivery was developed C_LIO_LIA novel syringe-mixing system for combining a gel with a liquid with subsequent dispensing of different volume units showed non-homogenous active ingredient distribution C_LIO_LIFinal optimised APOSECTM-APOgel formulation maintains functional wound-healing efficacy C_LI

This study presents the development of biodegradable intra-arterial drug delivery (IADD) devices for focal treatment of targeted organs, to enhance therapeutic efficacy while minimizing systemic toxicity. The IADD devices are fabricated using magnesium (Mg) and poly(glycerol sebacate) (PGS), leveraging their biocompatibility and tunable biodegradability, and are loaded with two model drugs, i.e., dexamethasone (DEX) or cisplatin (CIS). The IADD devices with helical and linear designs were fabricated for focal drug delivery to targeted organs and characterized for their microstructure and composition using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FTIR). The results confirmed the successful incorporation and stability of the drugs within the device. The IADD devices demonstrated a sustained release of DEX and CIS over 30 days in vitro, with cumulative release of 373.11 {+/-} 1.41 {micro}g and 64.73 {+/-} 0.06 {micro}g, respectively. The IADD devices demonstrated cytocompatibility with endothelial cells and sustained pharmacological activity against glioma cells throughout the in vitro release period. We implanted DEX-loaded IADD devices into the artery upstream of a target organ in rat models. The devices implanted into the renal artery to target the kidney and the carotid artery to target the brain achieved 109-fold and 68-fold improvements, respectively, in organ vs systemic drug levels compared to oral drug administration. These results proved the safety and efficacy of the IADD devices for sustained, focal drug delivery of different drugs to the target organs, with reduced systemic drug exposure. Overall, the results demonstrated the potential of the IADD devices as a valuable platform technology to achieve focal drug delivery to targeted organs for a wide range of clinical applications, especially for delivering drugs with high efficacy, high systemic side-effects, and narrow therapeutic window.

Flexible and textile-integrated electrochemical systems offer a convenient, user-friendly and non-invasive platform for continuous biochemical monitoring. In this study, a fully flexible and low-profile electrochemical system was developed by fabricating both the glucose biosensor and a compact potentiostat implemented on a polyimide (PI) filament circuit. The glucose biosensor was realized via direct laser writing (DLW), enabling precise electrode patterning and seamless integration with the potentiostat filament circuit. The integrated system exhibited a linear chronoamperometric response to glucose concentrations ranging from 0 to 0.25 mM in artificial sweat (AS). Further evaluation on cotton textiles soaked in AS and under mechanical bending confirmed stable performance, flexibility, and robustness. These findings highlight the potential of the PI-based potentiostat-sensor system for wearable, textile-integrated glucose monitoring and broader healthcare applications.

Treating extensive full-thickness burn wounds remains difficult in clinical practice because available donor skin is often limited, the risk of infection is high, and many standard dressings do not perform well when defects are large or structurally complex. These limitations have shifted attention to decellularized extracellular matrix (dECM) scaffolds, which can provide physical coverage while preserving biochemical cues that may support tissue repair. Based on this rationale, we designed a decellularization method that improves reagent penetration to produce a full-thickness porcine decellularized small intestine (dSI) scaffold for use in burn wound coverage. The protocol removed most cellular material while leaving low levels of detergent residue, and it maintained the native three-layer structure of the intestinal wall. Most key ECM components, such as collagen and glycosaminoglycans, were also retained. In this study, the dSI showed several properties relevant to burn care, capacity to absorb large amounts of fluid, water vapor transmission rates similar to those reported for skin, and resisted microbial penetration in vitro. From a mechanical standpoint, the scaffold retained anisotropic behaviour and remained stable under cyclic loading. This pattern indicates that it could withstand repeated deformation instead of acting like a fragile membrane. Degradation tests under enzymatic and oxidative conditions indicate that the material breaks down in a controlled way over a period that appears consistent with typical wound-healing timelines. In vitro assays indicated that the scaffold was cytocompatible, as human dermal fibroblasts and keratinocytes both attached to its surface and continued to proliferate. Cell responses differed depending on surface orientation, suggesting that preserved intestinal layers may shape cell behaviour in ways that are often missing in thinner or more uniform matrices. Overall, full-thickness dSI appears to act as a biologically active scaffold and shows mechanical properties that exceed those of many currently used burn dressings.

Three-dimensional (3D) bioprinted liver scaffolds offer a promising platform for drug screening, disease modelling, and regenerative medicine, yet their broader adoption is limited by the absence of robust post-fabrication preservation strategies. This study aimed to evaluate the impact of -80{degrees}C (deep freezer) preservation and evaluate the structural integrity and hepatic functionality of GelMA-decellularized liver extra cellular matrix (dECM)-based 3D bioprinted liver scaffolds. Bioinks were formulated using synthesized GelMA and solubilized rat liver dECM, and 3D scaffolds were fabricated via extrusion bioprinting into rectilinear grid scaffolds. The 3D scaffold preservations was performed by immersion into two different medium (the culture DMEM media and the other FBS-DMSO cocktail) was evaluated using MTT viability assay, and albumin assay. Preserved 3D bioprinted scaffolds retained overall architecture and cell distribution in the FBS-DMSO cocktail demonstrated by the live dead assay. Together, the data demonstrate that -80{degrees}C storage can maintain the basic cell viability ([~]80%) and a substantial fraction of liver-specific functionality in 3D bioprinted scaffolds but also highlight sensitivity to preservation-induced injury. These findings underscore the need for further optimization of cryoprotectant formulations and freezing protocols tailored to 3D bioprinted liver scaffolds, and provide a foundational framework for developing ready-to-use, cryopreserved 3D liver models for translational applications.

Pluripotent stem cells represent a potentially unlimited cell source for the fabrication of human bioartificial tissues to study and treat degenerative conditions such as type 1 diabetes. Alginate is widely used for mammalian cell immobilization and the primary hydrogel studied for pancreatic islet encapsulation. Rheological properties of alginate solutions or fully gelled forms are unsuitable as support matrix for embedded 3D printing. We describe partially gelled self-healing alginate formulations tuned for embedded 3D printing. Perfusable multi-plane hierarchical networks branching into 10 parallel channels, obtained by 3D printing of Pluronic F127 into the alginate support, show high fidelity to computer-assisted models. Therapeutic {beta}-cell doses (40x106 cells/mL) within centimeter-thick perfusable constructs remained viable for at least 1 week of culture under flow, with rapid insulin secretion detected upon glucose challenges. Stem cell-derived islet clusters cultured in 5-channel contructs for 25 days differentiated towards functional insulin-expressing cells. We describe a novel approach to generate cm-scale perfusable endocrine pancreatic constructs using sacrificial embedded 3D printing into alginate. This approach offers an adaptable platform to engineer perfusable cm-scale functional endocrine pancreatic tissues and potentially other vascularized bioartificial tissues.

Proteins orchestrate essential cellular processes, including metabolism, communication, survival, and regeneration, making proteomic profiling a powerful strategy to elucidate complex biological responses. Snail slime (SnS) has emerged as a bioactive material with documented pro-healing, antioxidant, and anti-inflammatory properties; however, its effects at the proteome level in normal human dermal fibroblasts (NHDFs) remain unexplored. In this study, an LC-MS-based proteomic approach (Data are available via ProteomeXchange with identifier PXD075292) combined with network and Gene Ontology enrichment analyses was employed to investigate SnS-induced molecular reprogramming in NHDFs, followed by functional assays. Results show that SnS is well tolerated for up to 72 h, confirming its cytocompatibility, followed by proteomic analysis revealing enrichment of biological processes related to apoptosis regulation, oxidative stress response, wound healing, cell migration, and anti-aging. Network analysis identified AKT, PI3K, SRC, and KRAS family members as key hub proteins, indicating convergence on central signaling pathways controlling survival, redox balance, and migratory activity. Functional assays demonstrated a time-dependent, controlled modulation of apoptosis consistent with cellular turnover, alongside a hormetic redox response characterized by transient ROS signaling followed by enhanced antioxidant capacity. Importantly, SnS significantly accelerated fibroblast migration, achieving complete wound closure within 24 h. Collectively, these findings demonstrate that SnS induces coordinated proteomic and functional reprogramming that integrates redox modulation, controlled apoptosis, and enhanced migration, providing a mechanistic basis for its pro-healing and anti-aging effects and supporting its potential as a regenerative biomaterial.

Apatite-based bone graft materials are widely used for bone regeneration; however, their limited bioactivity and slow remodeling often hinder complete replacement by newly formed bone. Electrical surface polarization has emerged as a promising non-chemical strategy to modify biomaterial surface properties without altering bulk characteristics. In this study, we investigated the effects of electrical surface polarization on apatite-based biomaterials using synthesized carbonate apatite (CA) for mechanistic in vitro evaluation and a clinically relevant xenograft material for in vivo validation. Material characterization confirmed the formation of B-type carbonate apatite with bone-like mineral composition. Thermally stimulated depolarization current measurements verified successful induction of surface charges, with polarization intensity dependent on treatment conditions. In vitro studies using human peripheral blood-derived osteoclast precursors demonstrated that electrically polarized CA surfaces significantly enhanced osteoclast differentiation and resorptive activity compared to non-polarized controls, with the strongest effects observed on positively polarized surfaces. Three-dimensional analysis revealed increased resorption pit depth and volume, indicating enhanced osteoclast functionality. In vivo implantation of polarized xenograft materials into rat femoral defects resulted in significantly increased new bone formation and improved implant-bone integration compared to non-polarized materials. Higher polarization conditions promoted more mature bone tissue formation and greater bone-material affinity. These results demonstrate that electrical surface polarization effectively modulates osteoclast-material interactions and enhances bone regeneration, highlighting its potential as a simple and translatable functionalization strategy for apatite-based bone graft materials.

The clinical success of vascular grafts relies on three main prerequisites: artery-tuned mechanics, cell-supportive microstructure, and a thromboresistant interface. Most current solutions address only a subset of this triad and equate mechanical matching with compliance alone, which can lead to disturbed hemodynamics, maladaptive mechanobiology, and adverse graft-host biochemical interactions that frequently culminate in clinical complications and graft failure. This study presents polyurethane-based heparin-functionalized elastomeric nanofibrillar grafts (H-ENGs) that integrate all three prerequisites while allowing multi-parameter mechanical mimicry. To address the principal failure mode of early thrombosis, a small fraction of polyethyleneimine (PEI) is added to the ENG electrospinning solution to form P-ENGs, enabling one-step covalent heparin conjugation to form H-ENGs. The decoupled design of the ENG platform preserves the biomimetic microstructure and mechanics following PEI incorporation and heparinization, enabling adaptable, indication-specific optimization. In vitro, H-ENGs exhibit good cytocompatibility with minimal hemolysis, platelet adhesion, and whole blood clotting. Pilot porcine abdominal aorta interposition studies demonstrate feasibility: H-ENGs exhibit favorable surgical handling, intact suture-line integrity, and anastomotic hemostasis under dynamic flow, and retain artery-tuned mechanics and surface heparin at two weeks. While further testing is warranted, these results indicate that H-ENGs satisfy the three prerequisites for vascular graft clinical success. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=68 SRC="FIGDIR/small/701857v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@1e09f2aorg.highwire.dtl.DTLVardef@1f1b5baorg.highwire.dtl.DTLVardef@1d1fba6org.highwire.dtl.DTLVardef@e066ca_HPS_FORMAT_FIGEXP M_FIG C_FIG

Buccal delivery offers a promising alternative to oral drug administration by enabling direct systemic absorption and avoiding first-pass metabolism. Multilayer polymeric films represent a promising strategy for the sequential delivery of drug and absorption enhancer in the oral cavity. Here, dual- and triple-layer films were fabricated via slot-die coating, incorporating a GLP-1 receptor agonist (GLP-1-RA) and the penetration enhancer sodium glycodeoxycholate (GDC). These were co-loaded in dual-layer films or compartmentalized in triple-layer films. Scanning electron microscopy and optical coherence tomography confirmed well-defined, distinct layers with thicknesses suitable for buccal administration (339 {+/-} 10.24 {micro}m and 487 {+/-} 36.5 {micro}m for dual- and triple-layer films, respectively). Both designs exhibited good mucoadhesion and mucosal compatibility, and preserved the secondary structure of GLP-1-RA. In vitro release studies showed rapid diffusion of GDC and GLP-1-RA from dual-layer films, whereas triple-layer films enabled sustained, sequential release of GDC and GLP-1-RA. Ex vivo porcine buccal mucosa studies showed higher GLP-1-RA and GDC flux from triple-layer films compared to dual-layer films. The films also did not compromise epithelial integrity, in contrast to the direct application of GLP-1-RA and GDC, which caused significant epithelial disruption. These results demonstrate that multilayer film architecture and spatial layering can be harnessed to control release kinetics, maximize peptide penetration, and minimize tissue stress, offering a versatile platform for safe and effective peptide delivery. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=93 SRC="FIGDIR/small/700335v1_ufig1.gif" ALT="Figure 1"> View larger version (25K): org.highwire.dtl.DTLVardef@76858borg.highwire.dtl.DTLVardef@1397e74org.highwire.dtl.DTLVardef@19d1841org.highwire.dtl.DTLVardef@a369c5_HPS_FORMAT_FIGEXP M_FIG C_FIG

Escherichia coli (E. coli) biofilms consist of bacteria, an extracellular matrix (ECM) mainly made of curli amyloid fibers, phosphoethanolamine-modified cellulose (pEtN-cellulose), and water. While curli amyloid fibers contribute to biofilm rigidity, pEtN-cellulose contributes to their cohesion. This work explores the interplay between these fibers, and how their interaction influence biofilm structure and mechanical properties. We performed a multiscale analysis on E. coli biofilms grown using strains producing curli and pEtN-cellulose, and only curli and only pEtN-cellulose in co-seeded ratios. Micro-indentation experiments, confocal microscopy, and cryo-FIBSEM 3D imaging revealed a composite-like behavior of the biofilm, where its mechanical properties depend on ECM composition and organization. Spectroscopic analysis of the extracted fibers showed that their biophysical properties are influenced by their pEtN-cellulose to curli ratio and assembly. We propose that pEtN-cellulose swelling is contrained by its interactions with rigid curli fibers. The reference E. coli strain maximizes this effect by assembling a curli/pEtN-cellulose hybrid material at the sub-micron scale, where its composition, interactions, and architecture can explain biofilm emergent properties. This knowledge on microbial ECM assembly opens new avenues for engineering living materials, especially for the use of bacterial biofilms as a source of bio-sourced materials.