The use of electrospun polymeric biodegradable materials for medical applications is becoming increasingly widespread. One of the most important parameters regarding the functionality of nanofiber scaffolds during implantation and the subsequent regeneration of damaged tissues concerns their stability and degradation behavior, both of which are influenced by a wide range of factors (the properties of the polymer and the polymer solution, the technological processing approach, the sterilization method, etc.). This study monitored the degradation of nanofibrous materials fabricated from degradable polyesters as a result of the sterilization method applied (ethylene oxide and gamma irradiation) and the solvent system used to prepare the spun polymer solution. Aliphatic polyesters PCL and PLCL were chosen for this study and selected with respect to the applicability and handling in the surgical setting of these nanofibrous materials for vascular bandaging. The results revealed that the choice of solvent system exerts a significant impact on degradation during sterilization, especially at higher gamma irradiation values. The subsequent enzyme-catalyzed degradation of the materials following sterilization indicated that the choice of the sterilization method influenced the degradation behavior of the materials. Whereas wave-like degradation was evident concerning ethylene oxide sterilization, no such behavior was observed following gamma-irradiation sterilization. With concern for some of the tested materials, the results also indicated the potential for influencing the development of degradation within the bulk versus degradation from the surface of the material. Both the sterilization method and the choice of the spinning solvent system were found to impact degradation, which was observed to be most accelerated in the case of PLCL (L-lactide-co-caprolactone copolymer) electrospun from organic acids and subsequently sterilized using gamma irradiation. Since we planned to use these materials in cardiovascular applications, it was decided that their hemocompatibility would also be tested. The results of these tests revealed that changes in the structures of the materials initiated by sterilization may exert thrombogenic and anticoagulant impacts. Moreover, the microscopic analysis suggested that the solvent system used in the preparation of the materials potentially affects the behavior of erythrocytes; however, no indication of the occurrence of hemolysis was detected.

Polypyrrole is one of the most investigated conductive polymers used for tissue engineering applications because of its advantageous properties and the ability to promote different cell types’ adhesion and proliferation. Together with β-cyclodextrin, which is capable of accommodating helpful biomolecules in its cavity, it would make a perfect couple for use as a scaffold for tissue engineering. Such scaffolds were prepared by the polymerisation of 6-(pyrrol-3-yl)hexanoic acid on polycaprolactone microfibres with subsequent attachment of β-cyclodextrin on the polypyrrole layer. The materials were deeply characterised by several physical and spectroscopic techniques. Testing of the cyclodextrin enriched composite scaffold revealed its better performance in in vitro experiments compared with pristine polycaprolactone or polypyrrole covered polycaprolactone scaffolds.

Background: Dupuytren’s disease (DD) is a common fibrotic disorder of the hand, characterized by progressive thickening and contracture of the palmar and digital fascia. Surgical excision remains the primary treatment; however, there are currently no therapies to prevent disease progression or recurrence. This study aims to develop a 3D in vitro model to test novel antifibrotic therapies. The model is based on decellularized pathological DD tissue seeded with patient-derived fibroblasts, capturing the role of both cellular and extracellular matrix components in disease progression. Methods: Fibrotic DD tissues were obtained from surgical excisions, sectioned, and decellularized. In parallel, primary fibroblasts were isolated from patient samples. The decellularized extracellular matrices (dECMs) were characterized with respect to biochemical composition, collagen structure, and mechanical properties. Fibroblasts were seeded onto the dECMs and cultured stepwise to initially promote proliferation, followed by differentiation into myofibroblasts. Secretomes of cells cultivated on the established 3D model were compared to those from conventional 2D cultivations. To evaluate the model´s relevance and effectiveness we tested the antifibrotic drug minoxidil. Results: The dECMs retained the pathological architecture and mechanical properties of native DD tissue, although individual ECM components were reduced after decellularization. Fibroblasts successfully adhered, proliferated, and repopulated the scaffold. The relevance of the 3D model was demonstrated by the presence of myofibroblasts with disease–relevant secretome. The responsiveness to the drug minoxidil was significantly more complex in the 3D model than in conventional 2D cultures. Conclusion: We demonstrated that dECM seeded with DD fibroblasts represents a relevant 3D in vitro model of Dupuytren’s disease. The model enables antifibrotic drug screening, as demonstrated by the testing of minoxidil. Our model provides a reproducible platform also suitable for the investigation of cells and ECM contributions to palmar fascial fibrosis.

Tissue engineering strategies aim to create bone models to enhance our understanding of bone development and improve bone repair. Endochondral ossification (EO), where cartilage is replaced by bone, is difficult to replicate. We developed a collagen–hyaluronic acid (HA) hydrogel system for a three-dimensional (3D) co-cultivation of human chondrocytes, human mesenchymal stem cell (hMSCs), and human umbilical vein endothelial cells (HUVECs) to model the early stages of EO. To our knowledge, this specific tri-culture configuration within such a hydrogel composition has not been previously reported, providing a novel platform for studying EO-related cellular and matrix interactions in vitro. Differentiation and migration of hMSCs and HUVECs were studied in collagen I (Col I) hydrogels, with or without the addition of collagen II (Col II), HA, and chondrocytes. Col II and HA enhanced cell osteogenic differentiation, as documented by an increased COL1A1 and ALPL gene expression and enhanced alkaline phosphatase activity. Chondrocytes further promoted osteogenic cell differentiation and temporarily enhanced hypertrophic and angiogenic signaling as evidenced by elevated MMP13 and VEGFA expression. Furthermore, elevated SOX9 expression and Alcian blue staining indicated a chondrogenic-supportive environment. These findings highlight the synergistic effects of osteogenic and chondrogenic signals, emphasizing the potential of combining Col I and Col II, HA, and essential cell types in hydrogels to optimize bone and cartilage tissue engineering.

Pulmonary artery banding is a surgical procedure performed when there is a shunt between the left and right ventricle. Its aim is to constrict the lumen of the pulmonary artery by using a band to reduce blood flow to the lungs. In this study, we report the results of investigating the mechanical properties of a composite composed of poly(L-lactide-co-ε-caprolactone) layers and a collagen matrix (PLCL-COLL). PLCL layers were obtained by electrospinning, impregnated with collagen solution, and finally cross-linked to increase the stiffness of the material. Bands of PLCL-COLL were implanted into a rat peritoneum and explanted after 1, 3, and 6 months in vivo. The mechanical properties of the material before and after implantation were determined using uniaxial tensile tests. The same was done with samples of strips prepared from GORE-TEX material. By comparing the results of tensile tests before implantation and after explantation, it was found that PLCL-COLL degrades in the rat's body and that it exhibits a mechanical response showing of elastic modulus values that correspond well to arterial biomechanics (elastic modulus measured in the initial linear region of the deformation was found to be: 4.14 MPa ± 1.11 MPa, 2.34 MPa ± 1.02 MPa, 1.11 MPa ± 0.77 MPa, and 0.88 MPa ± 0.60 MPa before implantation, and 1, 3, and 6 months after implantation respectively). Similar to the elastic modulus, the strength of the PLCL-COLL composite decreased during in vivo exposure (1.32 ± 0.32 MPa, 0.60 ± 0.26 MPa, 0.44 ± 0.11 MPa, and 0.46 ± 0.28 MPa before implantation, and 1, 3, and 6 months after implantation respectively). In our experiments, PLCL-COLL material was always more compliant than GORE-TEX (elastic modulus 34.7 MPa ± 2.06 MPa before implantation, and 9.35 MPa ± 6.80 MPa after implantation). The results suggest that PLCL-COLL could be a suitable candidate for the development of artery banding tapes, and also for further use in cardiovascular surgery.

Understanding how microorganisms interact with nanofibrous materials (NMs) is essential for designing functional surfaces, yet morphology–yeast interactions remain far less studied than bacterial systems. Here, we investigated how fiber diameter and secondary surface structuring of poly-ε-caprolactone (PCL) NMs affect yeast retention, adhesion, biofilm development, and cell transfer. Five PCL NMs were prepared from two PCL molecular weights (PCL45, PCL80) as smooth fibers and as structured fibers generated by two distinct post-processing routes: polymer-spray-induced texturing (PCL45_80, PCL80_80) and enzymatic surface restructuring (PCL80_E). Interactions with model yeasts (Candida albicans ATCC 10231 and ATCC 90028; Saccharomyces cerevisiae ATCC 9763 and CCM 8381) were assessed by retention, biofilm biomass and metabolic activity during static growth (2 h, 24 h, 72 h), and SEM imaging; cell transfer from colonized agar to NMs was measured using an adapted agar-mesh assay. All tested PCL NMs exhibited high retention (84.7–100%), regardless of fiber diameter or secondary structures. Material-dependent differences were most pronounced during early adhesion, whereas biofilm formed on all NMs and its biomass was strongly strain-specific. Overall, NMs with larger fiber diameter (PCL80 series) supported denser yeast colonization than PCL45, while the secondary structures used here did not confer antifungal activity nor enhance biofilm formation. For cell transfer, PCL45_80 exhibited the highest attachment potential, yet ∼50 % of cells remained on the donor surface. Collectively, these results show that PCL nanofiber morphology modulates yeast–surface interactions primarily by tuning early attachment and colonization capacity.