A hybrid scaffold was obtained by the deposition of a thin network of submicron fibrin fibrils on the microporous walls of a macroporous poly(L-lactide) (PLLA) three-dimensional structure. The fibrin coating is homogeneous across the entire substrate and allowed the pore structure remain open in the hybrid scaffold. The elastic modulus of the hybrid scaffold (0.65 MPa) was increased up to twofold compared to the pure PLLA scaffold (0.29 MPa). Mouse pre-osteoblastic cells, MC3T3, were seeded on both pure PLLA and hybrid scaffolds, and cultured for 3, 6, and 24 h. The coating enhanced the cell colonization and proliferation and provided a more homogeneous distribution of cells within the scaffolds. In addition, the coating improved the scaffold adhesion properties by supplying new binding sites to the cells that modify the transmembrane receptors involved in initial cell adhesion mechanism. The expression of the β3 integrin was observed in cells cultured on fibrin-coated scaffolds instead of the α5 integrin, which was expressed in the uncoated scaffold. These hybrid PLLA/fibrin scaffolds have cell culture features suitable to promote early tissue regeneration.

Abstract. Polycaprolactone scaffolds were produced by electrospinning. Polymeric solutions in a mix of dichloromethane and dimethylformamide were electrospun to form fibers in the sub-micron range. Physical properties of the polycaprolactone solutions were characterized with respect to density, viscosity, conductivity and surface tension. Processing was optimized following Taguchi's methodology to select the set of processing parameters that resulted in producing fibers with the smallest diameters, minimum number of defects and with the narrowest distribution of fiber diameter. Morphology of electrospun fibers was qualitatively and quantitatively analyzed for the different sets of processing parameters. The optimum conditions found to electrospun polycaprolactone were used to process polycaprolactone solutions containing nano-particles of hydroxyapatite or bioactive glass. Bioactivity of nano-composite electrospun membranes in simulated body fluid was analyzed and biological response was tested by assessing proliferation and viability of MT3C3-E1 preosteoblasts cultured on polycaprolactone and its nanocomposite membranes.

The aim of this study was to develop a biocompatible monolayer substrate based on fibrin and chitosan for in vitro culture of chondrocytes. Fibrin-chitosan composite substrates combined the proved cell adhesion properties of fibrin with the hydrophilicity and poor adhesion capacity of chitosan. Chitosan microspheres were produced by coacervation method, agglomerated within a fibrin network and subsequently crosslinked with genipin. The composite substrate was stable for 28 days of culture due to the high crosslinking density. Human chondrocytes cultured on the composite substrate were viable during the culture period. At the end of culture time (28 days) the composite substrate showed low cellular proliferation, 41% more collagen type II and 13% more production of sulfated glycosaminoglycans with respect to the amounts found at 14 days. The study revealed that dedifferentiated chondrocytes cultured in monolayer on the composite substrate can re-acquire characteristics of differentiated cells without using three-dimensional substrates or chondrogenic media.

Purpose To analyze the ability of adhesion of adipose‐derived adult stem cells (ADAS) to porous materials made of chitosan for the future design of biodegradable autologous membranes for the treatment of ocular surface pathologies Methods We used porous chitosan scaffolds prepared by cold neutralization in a 4% chitosan aqueous solution at acid pH, some of the materials were treated with argon plasma to favour cell adhesion. ADAS cells were obtained after adipose tissue processing from patients undergoing liposuction surgery. 5,000 cells were seeded per each scaffold in DMEM/F12 medium and cellular growth was analyzed on these materials by scanning electron microscopy (SEM) after ten days in culture. Results Adhesion was observed and cell growth was optimal on the surface of non‐plasma‐treated biomaterials. Chitosan scaffolds treated with argon plasma showed better adhesion properties. Extracellular matrix production was also observed Conclusion 4% chitosan biomaterials allow for adhesion, proliferation and extracellular matrix production of ADAS cells. Biocolonization of these biomaterials with ADAS cells will imply the future design of biological autologous membranes containing cells from the very same patient that would act as patches for the treatment of ocular surface pathologies for which current treatments show certain risks such immune rejection, infections or low effectivity.