Conductive hydrogels have gained interest in biomedical applications and soft electronics. To tackle the challenge of ionic hydrogels falling short of desired mechanical properties in previous studies, our investigation aimed to understand the pivotal structural factors that impact the conductivity and mechanical behavior of polyethylene glycol (PEG)-based hydrogels with ionic conductivity. Polyether urethane diacrylamide (PEUDAm), a functionalized long-chain macromer based on PEG, was used to synthesize hydrogels with ionic conductivity conferred by incorporating ions into the liquid phase of the hydrogel. The impact of salt concentration, water content, temperature, and gel formation on both mechanical properties and conductivity was characterized to establish parameters for tuning hydrogel properties. To further expand the range of conductivity available in these ionic hydrogels, 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) was incorporated as a single copolymer network or double network configuration. As expected, conductivity in these ionic gels was primarily driven by ion diffusivity and charge density, which were dependent on hydrogel network formation and swelling. Copolymer network structure had minimal effect on the conductivity, which was primarily driven by counter-ion equilibrium; however, the mechanical properties and equilibrium swelling were strongly dependent on network structure. The structure-property relationships elucidated here enable the rationale design of this new double network hydrogel to achieve target properties for a broad range of biomedical applications.

The high bioactivity and biocompatibility of hydroxyapatite (HAP) make it a useful bone graft material for bone tissue engineering. However, the development superior osteoconductive and osteoinductive materials for bone regeneration remains a challenge. To overcome these constraints, Cu-doped hydroxyapatite (HAP(Cu)) from waste eggshells has been produced for bone tissue engineering. The materials produced were characterized using Fourier transform infrared spectroscopy, x-ray diffraction, and photoelectron spectroscopy. The scanning microscopy images revealed that the developed HAP was a rod-like crystalline structure with a typical 80-150 nm diameter. Energy-dispersive x-ray spectroscopy showed that the generated HAP was mostly composed of calcium, oxygen, and phosphorus. The Ca/P molar ratios in eggshell-derived and copper-doped HAP were 1.61 and 1.67, respectively, similar to the commercially available HAP ratio (1.67). The WST-8 assay was used to assess the biocompatibility of HAPs with hBMSCs. HAP(Cu) in the media significantly altered the cytotoxicity of biocompatible HAP(Cu). The osteogenic potential of HAP(Cu) was demonstrated by greater mineralization than that of pure HAP or the control. HAP(Cu) showed higher osteogenic gene expression than pure HAP and the control, indicating its stronger osteogenic potential. Furthermore, we assessed the effects of sample-treated macrophage-derived conditioned medium (CM) on hBMSCs' osteogenesis. CM-treated HAP(Cu) demonstrated a significantly higher osteogenic potential vis-à-vis pure HAP(Cu). These findings revealed that HAP(Cu) with CM significantly improved osteogenesis in hBMSCs and can be explored as a bone graft in bone tissue engineering.

Nanoparticle-laden contact lenses are a formidable strategy for ocular drug delivery. However, incorporating nanoparticles to achieve sustained drug release without affecting the contact lenses' properties remains a challenging task. In this work, daily and monthly replacement silicone-hydrogel contact lenses laden with bovine serum albumin/hyaluronic acid (BSA/HA) nanoparticles are presented. These nanoparticle-laden contact lenses enable the sustained release of 5-fluorouracil (5-FU) in mimetic physiological conditions. The nanoparticle-laden contact lenses display properties similar to neat contact lenses, including refractive index, water content, UV/visible transmittance and chemical structure. Noteworthy attributes include the BSA/HA nanoparticles' low polydispersity, negative surface charge and a hydrodynamic size of ~210 nm, as well as the high nanoparticle loading efficiency (~ 30%) of the contact lenses. Thereby, the BSA/HA nanoparticles are a promising strategy for developing nanoparticle-laden contact lenses for therapeutic applications, namely for sustained drug delivery.

Spinal fusion is the ultimate choice for most patients with severe disc degeneration, and bone tissue engineering offers novel strategies to improve intervertebral bone growth and fusion. In this study, we utilized graphene oxide (GO) and methacrylated gelatin (GelMA) to prepare GelMA/GO composite hydrogel scaffolds with different GO concentrations. By characterizing the various properties of the scaffolds, it was learned that the composite scaffold containing 1.2 mg/mL GO possessed the best overall performance, and we used it for subsequent experiments. GelMA/GO composite scaffolds containing different bone-forming peptide-1 (BFP-1) concentrations were constructed and cocultured with bone marrow mesenchymal stem cells (BMSCs), and the results showed that GelMA/GO composite scaffolds containing 0.4 mg/mL BFP-1 induced the cells to produce more ALP and mineralized matrix. The above scaffold was further investigated as a GelMA/GO@BFP-1 composite, and the results showed that it promoted the production of ALP and mineralized matrix in BMSCs, and significantly enhanced the expression of osteogenesis-related genes (ALP, Runx-2, OCN, OPN) and proteins (Runx-2, OCN). It suggests that the GelMA/GO@BFP-1 complex promotes osteogenic differentiation of BMSCs and has the potential tobe used as a bone implant for improving intervertebral bone fusion.

This study developed a shape memory polyurethane foam (SM-PUF) with tunable mechanical properties and exceptional radiation tolerance for potentially implanting tissue defects after mastectomy. The PUFs were synthesized via an in situ foaming strategy using water as a foaming agent, incorporating 4,4'-diphenylmethane diisocyanate (MDI) as the rigid segment and both polyoxytetramethylene glycol and polycaprolactone as the soft segment. The resultant PUFs possess an open-cell structure with a pore size of 30 ~ 800 μm, which achieves a compressive stress of 0.04 MPa under 70% compression strain and a tensile elongation of 667.9%. PUFs exhibit body temperature (37°C)-responsive softening and shape memory abilities, with recovery and fixation ratios reaching 88% and 98%, respectively. It was verified that PUFs can resist 40 Gy radiotherapy without changing their mechanical properties and biocompatibility. This study introduces an innovative approach to produce customizable foam for the reconstruction of implant prostheses for the breast.

Premature implant failure, a critical concern in biomedical applications, is often attributed to poor biocompatibility and vulnerability to bacterial colonization. These issues are addressed by creating an endoprosthetic material with natural biocompatibility and antibacterial properties. In this in vitro study, the relaxed and unrelaxed tetrahedral amorphous carbon (ta-C) coatings were examined, both fabricated by the improved patented Pulsed Laser Deposition (PLD) technology. The chemical composition, surface roughness, hardness, topography, and wettability were analyzed. The ta-C surfaces were incubated by MM6 cells, E. coli and S. capitis bacteria for 24 h. PCR assessed the inflammatory response in MM6 cells, while fluorescence microscopy quantified adhering bacteria, and scanning electron microscopy examined local adhesion behavior. The results demonstrate comparable carbon phase composition, wettability properties, and hardness for both relaxed and unrelaxed ta-C. However, relaxed ta-C coating exhibited significantly fewer defects in terms of both quantity and quality, along with an antibacterial effect against E. coli. This suggests that the relaxed ta-C coating could contribute to the development of an endoprosthesis, preventing adverse biological reactions and implant-related infections, thus improving the longevity of the prosthesis.

Many patients suffer from peripheral nerve injury, which can impair their quality of life. Restoring nerve tissue is difficult due to the low ability of nerves to regenerate. Nerve conduits are designed to help peripheral nerve regeneration by providing a scaffold that can match the tissue characteristics, facilitate cellular activities, and be easily implanted. In order to provide a nerve conduit having scaffolding properties, conductance cytocompatibility, we have investigated the potential of channeled structures made of poly (glycerol-sebacate) (PGS) elastomer containing carbon nanofibers (CNFs) in the regeneration of nerve tissue. The first step was to synthesize PGS elastomer and tune its properties to match the nerve tissue. Then, a carbon dioxide laser was used to create micro channels on the elastomer surface for guiding nerve cells. The PGS elastomer was blended with carbon nanofiber (CNF), which was functionalized to bond with the elastomer, to form a conductive structure. The constructs were investigated in terms of cell behavior using PC12 and S42 cell lines. A statistically significant increase in cell proliferation was observed in both cell lines. It was found that the cells began to grow along the canal in places. In terms of elasticity, conductance and cell response, these constructs may be a potential candidate for nerve tissue engineering.

Over the past decade, there has been growing interest in developing microspheres for embolization procedures. However, the lack of noninvasive monitoring of the embolic agents and the occurrence of reflux phenomenon leading to unintentional occlusions has raised concerns regarding their compatibility/suitability for embolization therapy. Here we report the development of specialty microspheres having intrinsic radiopacity and surface functionality to tackle the existing complications that pave the way for more advanced solutions. To achieve the above goal, an iodinated monomer, termed "IBHV," capable of imparting radiopacity and functionality, was synthesized and used as a chain extender to make radiopaque polyurethane. Microspheres with a smooth surface and an average diameter of 474 ± 73 μm were fabricated from this polyurethane. The microspheres obtained were noncytotoxic, had a permissible hemolysis rate, and showed better traceability on x-ray imaging. Subsequent immobilization of thrombin onto microspheres improved their hemostatic effect. This study demonstrated that immobilization of thrombin would lead to microspheres with unique traits of radiopacity and hemostatic properties, which will undoubtedly enhance embolization efficiency.

Substrate topography is vital in determining cell growth and fate of cellular behavior. Although current in vitro studies of the underlying cellular signaling pathways mostly rely on their induction by specific growth factors or chemicals, the influence of substrate topography on specific changes in cells has been explored less often. This study explores the impact of substrate topography, specifically the tricot knit microfibrous structure of alumina textiles, on cell behavior, focusing on fibroblasts and keratinocytes for potential wound healing applications. The textiles, studied for the first time as in vitro substrates, demonstrated support for keratinocyte adhesion, leading to alterations in cell morphology and the expression of E-cadherin and fibronectin. These topography-induced changes resembled the epithelial-to-mesenchymal transition (EMT), crucial for wound healing, and were specific to keratinocytes and absent in identically treated fibroblasts. Biochemically induced EMT in keratinocytes cultured on flat alumina substrates mirrored the changes seen with alumina textiles alone, suggesting the tricot knit microfibrous topography could serve as an in vitro model system to induce EMT-like mechanisms. These results enhance our understanding of how substrate topography influences EMT-related processes in wound healing, paving the way for further evaluation of microfibrous alumina textiles as innovative wound dressings.

Multidrug resistance remains one of the major challenges in breast cancer research, often leading to treatment failure. To better understand this mechanism, sophisticated three-dimensional (3D) tumor models are necessary, as they offer several advantages over traditional bidimensional (2D) cultures. In this study, poly-l-lactic-acid porous scaffolds were produced using a thermally induced phase separation technique and employed as 3D models for breast cancer cell lines: MDA-MB-231, MCF-7, and its multidrug-resistant variant, MCF-7R. The MTS assay was used to compare growth inhibition following doxorubicin treatment in 2D and 3D. Remarkably, the IC values increased in 3D cultures compared to 2D: MDA-MB-231 (445 vs. 54.5 ng/mL), MCF-7 (7.45 vs. 0.75 μg/mL), and MCF-7R (165 vs. 39 μg/mL). MCF-7R, which usually shows greater resistance in 2D, demonstrated even higher resistance in 3D. In fact, IC was not reached within 3 days as with the other models, but only after 6 days. Cellular morphology also played a crucial role. When treated with concentrations higher than the IC, MDA-MB-231 cells lost their physiological 3D clustered structure, while MCF-7 and its resistant variant exhibited disrupted layers. All cell lines in 3D showed higher chemoresistance, suggesting a more biomimetic spatial architecture. Our work bridges the gap between monolayer and animal models, highlighting the potential of polymeric 3D scaffolds in breast cancer research.

3D bioprinting can generate the organized structures found in human skin for a variety of biological, medical, and pharmaceutical applications. Challenges in bioprinting skin include printing different types of cells in the same construct while maintaining their viability, which depends on the type of bioprinter and bioinks used. This study evaluated a novel 3D bioprinted skin model containing human keratinocytes (HEKa) and human dermal fibroblasts (HDF) in co-culture (CC) using a high-viscosity fibrin-based bioink produced using the BioX extrusion-based bioprinter. The constructs containing HEKa or HDF cells alone (control groups) and in CC were evaluated at 1, 10, and 20 days after bioprinting for viability, immunocytochemistry for specific markers (K5 and K10 for keratinocytes; vimentin and fibroblast specific protein [FSP] for fibroblasts). The storage, loss modulus, and viscosity properties of the constructs were also assessed to compare the effects of keratinocytes and fibroblasts individually and combined, providing important insights when bioprinting skin. Our findings revealed significantly higher cell viability in the CC group compared to individual keratinocyte and fibroblast groups, suggesting the combined cell presence enhanced survival rates. Additionally, proliferation rates of both cell types remained consistent over time, indicating non-competitive growth within the construct. Interestingly, keratinocytes exhibited a greater impact on the viscoelastic properties of the construct compared to fibroblasts, likely due to their larger size and arrangement. These insights contribute to optimizing bioprinting strategies for skin tissue engineering and emphasize the important role of different cell types in 3D skin models.

In recent years, the exploration of sustainable alternatives in the field of bone tissue engineering has led researchers to focus on marine waste byproducts as a valuable resource. These marine resources, often overlooked remnants of various industries, exhibit a rich composition of hydroxyapatite, collagen, calcium carbonate, and other minerals essential to the complex framework of bone structure. Marine waste by-products can emit gases such as methane and carbon dioxide, highlighting the urgency to repurpose these materials for innovative tissue regeneration solutions, offering a sustainable approach to address environmental challenges while advancing medical science. Using these discarded materials offers a promising pathway for sustainable development in regenerative medicine. This review investigates the distinctive properties of marine waste byproducts, emphasizing their capacity to be recycled effectively to contribute to the rebuilding of bone and cartilage tissue during regeneration processes. We also highlight the compatibility of these resources with biological materials such as platelet-rich plasma (PRP), stem cells, exosomes, and natural bioproducts, as well as nanoparticles (NPs) and polymers. By using the natural potential of these resources, we simultaneously address environmental challenges and promote innovative solutions in skeletal tissue engineering, initiating a new era of environmentally green biomedical research.

In vitro assessment of small-diameter synthetic vascular grafts usually uses standard cell culture conditions with early-passage cells. However, these conduits are mainly implanted in elderly patients and are subject to complex cellular interactions influenced by age and inflammation. Understanding these factors is central to the development of vascular grafts tailored to the specific needs of patients. In this study, the effects of aged endothelial cells subjected to pro- and anti-inflammatory agents and cultivated on a newly developed biodegradable electrospun thermoplastic polyurethane/poly(urethane-urea) blend (TPU/TPUU), on clinically available expanded polytetrafluorethylene (ePTFE), and on decellularized extracellular matrix (dECM) grafts were investigated. Young and aged endothelial cells were exposed to pro- and anti-inflammatory agents and characterized by morphology, migration capacity, and gene expression. In addition, the cells were seeded onto the various graft materials and examined microscopically alongside gene expression analyses. When exposed to pro-inflammatory cytokines, young and aged cells demonstrated signs of endothelial activation. Cells seeded on ePTFE showed reduced attachment and increased expression of pro-inflammatory genes compared with the other materials. dECM and TPU/TPUU substrates provided better support for endothelialization with aged cells under inflammatory conditions compared with ePTFE. Moreover, TPU/TPUU showed positive effects on reducing pro-thrombotic and pro-inflammatory gene expression in endothelial cells. Our results thus emphasize the importance of developing new synthetic graft materials as an alternative for clinically used ePTFE.

Local implantation or supplementation of magnesium gluconate (MgG) is being investigated as an effective approach to bone repair. Although studies have highlighted the possible mechanisms in Mg ion-stimulated new bone formation, the role of MgG in healing bone defects and the signaling mechanisms are not yet completely understood. In this study, we explored how supplemental MgG has bone-specific beneficial effects by delivering MgG locally and orally in animal models. We fabricated MgG-incorporated (CMC-M) and -free chitosan (CMC) scaffolds with good microstructures and biocompatible properties. Implantation with CMC-M enhanced bone healing in rat model of mandible defects, compared with CMC, by activating Wnt signals and Wnt-related osteogenic and angiogenic molecules. Oral supplementation with MgG also stimulated bone healing in mouse model of femoral defects along with the increases in Wnt3a and angiogenic and osteogenic factors. Supplemental MgG did not alter nature bone accrual and bone marrow (BM) microenvironment in adult mouse model, but enhanced the functioning of BM stromal cells (BMSCs). Furthermore, MgG directly stimulated the induction of Wnt signaling-, angiogenesis-, and osteogenesis-related molecules in cultures of BMSCs, as well as triggered the migration of endothelial cells. These results suggest that supplemental MgG improves bone repair in a way that is synergistically enhanced by Wnt signal-associated angiogenic and osteogenic molecules. Overall, this study indicates that supplemental MgG might ameliorate oxidative damage in the BM, improve the functionality of BM stem cells, and maintain BM-microenvironmental homeostasis.

Calcium phosphate cement (CPC) has evolved as an appealing bone substitute material, especially since CPCs were combined with poly(lactic-co-glycolic acid) (PLGA) porogens to render the resulting CPC/PLGA composite degradable. In view of the multiple variables of CPC and PLGA used previously, the effect of CPC composition and PLGA porogen morphology (i.e., microspheres versus microparticles) on the biological performance of CPC/PLGA has not yet been investigated. Consequently, we here aimed to evaluate comparatively various CPC/PLGA formulations varying in CPC composition and PLGA porogen morphology on their performance in a rabbit femoral condyle bone defect model. CPCs with a composition of 85 wt% α-TCP, 15 wt% dicalcium phosphate anhydrate (DCPA) and 5 wt% precipitated hydroxyapatite (pHA), or 100 wt% α-TCP were combined with spherical or irregularly shaped PLGA porogens (CPC/PLGA ratio of 60:40 wt% for all formulations). All CPC/PLGA formulations were applied via injection in bone defects, as created in the femoral condyle of rabbits, and retrieved for histological evaluation after 6 and 12 weeks of implantation. Descriptive histology and quantitative histomorphometry (i.e., material degradation and new bone formation) were used for analyses. Descriptively, all CPC/PLGA formulations showed material degradation at the periphery of the cement within 6 weeks of implantation. After 12 weeks, bone formation was observed extending into the defect core, replacing the degraded CPC/PLGA material. Quantitatively, similar material degradation (up to 87%) and new bone formation (up to 28%) values were observed, irrespective of compositional variations of CPC/PLGA formulations. These data prove that neither the CPC compositions nor the PLGA porogen morphologies as used in this work affect the biological performance of CPC/PLGA formulations in a rabbit femoral condyle bone defect model.

This pilot study investigated the potential of aloe vera (AV) to promote neurite outgrowth in organotypic dorsal root ganglia (DRG) explants (n = 230) from neonatal rats (n = 15). Using this in vitro model of acute axotomy, we assessed neurite outgrowth exceeding 1.5 times the explant diameter (viable explants) and measured the longest neurite length. These parameters were evaluated under control conditions and in cultures supplemented with commercial AV and four aligned scaffolds: poly-L-lactate (PLLA), polydioxanone (PDS), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and blended PHBV/AV. After 6 days of culture, explants were immunostained using neuron-specific marker Tuj1 and Schwann cell marker S100. Measurements were obtained with Image J software and analyzed using Jamovi 2.3. In control and AV dilution media, the study revealed radial tissue growth from the explant body with randomly oriented neurites, whereas in all scaffolds, bidirectional tissue growth occurred parallel to nanofibers. Binomial logistic regression analyses indicated that viable explants were more likely in the control group compared to PDS (p = 0.0042) and PHBV (p < 0.0001), with non-significant differences when compared to AV dilution, PLLA, and PHBV/AV. AV dilution showed a greater association with viable explants than PLLA (p = 0.0459), while non-significant difference was found between AV dilution and PHBV/AV. Additionally, the PHBV/AV scaffold predicted higher odds of viable explants than PLLA (p = 0.0479), PDS (p = 0.0001), and PHBV (p < 0.0001). Groups with similar probabilities of obtaining viable explants (control, AV dilution, and PHBV/AV) exhibited non-significant differences in their longest neurite lengths. In conclusion, control, AV dilution, and PHBV/AV yielded the highest probability of developing viable explants and the longest neurite lengths. This is the first study demonstrating the direct permissiveness of AV for axonal outgrowth. Furthermore, the blended PHBV/AV scaffold showed significant potential as a suitable scaffold for axonal regrowth and Schwann cell migration, ensuring controlled tissue formation for tissue engineering applications.

Tin-silver (Sn-Ag) has been used as a permanently implanted biomaterial within the Essure female sterilization device and in dental amalgams; however, little data exist for Sn-Ag's corrosion characteristics and/or cellular interactions. In this study, to assess its suitability as a degradable metallic biomaterial, 95-5 wt% Sn-Ag solder was subjected to corrosion testing including open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and anodic potentiodynamic polarization in phosphate-buffered saline (PBS) and cell culture media (with serum proteins) at room temperature (25°C) and body temperature (37°C). Cell culture studies were also performed. Mouse pre-osteoblast cells (MC3T3-E1) were cultured in media on Sn-Ag discs and monitored over 24 h at potentials below, around, or above Sn-Ag's breakdown potential, fixed, and then viewed using SEM. Separately, cells on tissue culture plastic were subjected to increasing concentrations of SnCl in media for 24 h before a live-dead imaging at each concentration to determine cell viability and area fraction covered when compared with a control well. The results show both passive (in PBS), with a breakdown potential of -250 mV versus Ag/AgCl and active polarization behavior (in AMEM with proteins). EIS results showed polarization resistance (R) in the 10 Ωcm range but decreased generally with increasing temperature (p < 0.05). Cells were well attached on Sn-Ag surfaces at OCP and below the breakdown potential, but when anodically polarized, cells reduced their spread area and became more spherical, indicating less viability. SnCl exhibited a dose-dependent killing effect on MC3T3 cells with a lethal dose for 50% of about 0.5 mM. The results of these experiments show that Sn-Ag alloys can be considered as degradable metallic biomaterials.

The vitreous humor undergoes liquefaction with age, resulting in complications that may require a vitrectomy, or surgical removal of the vitreous from the eye. Silicone oil, a common vitreous substitute, lacks properties similar to the natural vitreous. In particular, it lacks antioxidants that may be necessary to reduce oxidative stress in the eye. The purpose of this study was to evaluate antioxidant-loaded hydrogel vitreous substitutes in a pilot in vivo study. Ascorbic acid and glutathione were loaded into synthesized PEGDA hydrogels. Following vitrectomy, experimental antioxidant hydrogels or silicone oil were injected into one eye of rabbits, while the other eye served as untreated or sham control. Ophthalmic assessments, including electroretinography, were performed. Levels of glutathione and ascorbic acid were higher in the eyes treated with the antioxidant-loaded hydrogel vitreous substitute, although this was not found to be significant after 28 days. There were no statistically significant differences between groups with respect to clinical examination, and ocular health scores, electroretinograms, and histology were normal. These results indicate minimal concerns for the hydrogel formulation or high levels of antioxidants. Future research will assess the capability of vitreous substitutes to prolong antioxidant release, with the goal of minimizing cataract after vitrectomy.

Magnetic nanoparticles (MNPs) are produced for both diagnosis and treatment due to their simultaneous availability in magnetic resonance imaging (MRI) and magnetic hyperthermia (MHT). Extensive investigations focus on developing MNPs for individual MHT or MRI applications, but the development of MNPs for theragnostic applications has received very little attention. In this study, through efficient examination of synthesis conditions such as metal precursors, reaction parameters, and solvent choices, we aimed to optimize MNP production for effective utilization for MHT and MRI simultaneously. MNPs were synthesized by thermal decomposition under 17 different conditions and deeply characterized by transmission electron microscopy (TEM), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS). The heating efficiency of MNPs under an alternating current (AC) magnetic field was quantified, while MRI performance was evaluated through agar phantom experiments. Our findings highlight the crucial role of benzyl ether in metal ion reduction and size control. Metal-doped iron oxide MNPs displayed promise for MHT, whereas Mn-doped iron oxide MNPs exhibited enhanced MRI capabilities. Consequently, five engineered MNPs were considered potential candidates for further studies, demonstrating their dual ability in MRI and MHT.

The alveolar-capillary interface is the key functional element of gas exchange in the human lung, and disruptions to this interface can lead to significant medical complications. However, it is currently challenging to adequately model this interface in vitro, as it requires not only the co-culture of human alveolar epithelial and endothelial cells but mainly the preparation of a biocompatible scaffold that mimics the basement membrane. This scaffold should support cell seeding from both sides, and maintain optimal cell adhesion, growth, and differentiation conditions. Our study investigates the use of polycaprolactone (PCL) nanofibers as a versatile substrate for such cell cultures, aiming to model the alveolar-capillary interface more accurately. We optimized nanofiber production parameters, utilized polyamide mesh UHELON as a mechanical support for scaffold handling, and created 3D-printed inserts for specialized co-cultures. Our findings confirm that PCL nanofibrous scaffolds are manageable and support the co-culture of diverse cell types, effectively enabling cell attachment, proliferation, and differentiation. Our research establishes a proof-of-concept model for the alveolar-capillary interface, offering significant potential for enhancing cell-based testing and advancing tissue-engineering applications that require specific nanofibrous matrices.

The majority of issues related to patients suffering from conductive hearing loss and repeated otitis media are due to chronic tympanic membrane perforations. This generally requires a surgical procedure called tympanoplasty to seal the perforation where autologous grafts are used to reconstruct the membrane. However, the limitations associated with surgical procedures and the limited graft-material availability often cause difficulties in this route; demanding novel procedures or materials. The basic requirements for a synthetic graft-material for this application cover excellent cell adherence with no immune response and inflammatory actions at the site of implantation along with wound-healing characteristics and sufficient acoustic and mechanical properties. With this aim, an innovative graft material has been developed with polyvinyl alcohol (PVA) as the base component through this work. To ensure better cell adhesion and proliferation, a natural polymer, gelatin, has been cross-linked with PVA through a maleic anhydride (MA) intermediate; with a two-step synthesis protocol. The mechanical strength of graft material has been found to be tunable by adjusting the ratio of gelatin with PVA. Laser Doppler Vibrometry (LDV) has been employed to evaluate its acoustic properties upon exposure to a frequency sweep of 10-8000 Hz. The in vitro biocompatibility assays using L929 and RPMI 2650 cells substantiate the material's compatibility; ensuring its potential clinical applications toward chronic tympanic membrane perforations.