The introduction and designing of functional thermoresponsive hydrogels have been recommended as recent potential therapeutic approaches for biomedical applications. The development of bioactive materials such as thermosensitive gelatin-incorporated nano-organic materials with a porous structure and photothermally triggerable and cell adhesion properties may potentially achieve this goal. This novel class of photothermal hydrogels can provide an advantage of hyperthermia together with a reversibly transformable hydrogel for tissue engineering. Polypyrrole (Ppy) is a bioorganic conducting polymeric substance and has long been used in biomedical applications owing to its brilliant stability, electrically conductive features, and excellent absorbance around the near-infrared (NIR) region. In this study, a cationic photothermal triggerable/guidable gelatin hydrogel containing a polyethylenimine (PEI)–Ppy nanocomplex with a porous microstructure was established, and its physicochemical characteristics were studied through dynamic light scattering, scanning electronic microscopy, transmission electron microscopy, an FTIR; and cellular interaction behaviors towards fibroblasts incubated with a test sample were examined via MTT assay and fluorescence microscopy. Photothermal performance was evaluated. Furthermore, the in vivo study was performed on male Wistar rat full thickness excisions model for checking the safety and efficacy of the designed gelatin–PEI–Ppy nanohydrogel system in wound healing and for other biomedical uses in future. This photothermally sensitive hydrogel system has an NIR-triggerable property that provides local hyperthermic temperature by PEI–Ppy nanoparticles for tissue engineering applications. Features of the designed hydrogel may fill other niches, such as being an antibacterial agent, generation of free radicals to further improve wound healing, and remodeling of the promising photothermal therapy for future tissue engineering applications.

3D Bioscaffold with relative high mechanical property was developed using rabbit ADSCs.

Herein, we report the cartilage tissue engineering application of nanographene oxide (NGO)-reinforced gelatin hydrogel fabricated by utilizing a microplasma-assisted cross-linking method. NGO sheets with surface functionalities were introduced to enhance the mechanical and biomedical properties of gelatin-based hydrogels. Highly energetic reactive radicals were generated from the nonthermal plasma (NTP), which is used to facilitate the cross-linking and polymerization during the polymeric hydrogel fabrication. The NTP treatment substantially reinforced a small amount (1 wt %) of NGO into the gelatin hydrogel. Systematic material characterization thus shows that the fabricated hydrogel possessed unique properties such as moderate surface roughness and adhesiveness, suitable pores sizes, temperature-dependent viscoelasticity, and controllable degradability. In vitro studies demonstrated that the as-fabricated hydrogel exhibited excellent cell–material interactions with SW 1353 cells, bone marrow-derived mesenchymal stem cells, and a rat chondrocyte cell line, thereby exhibiting appropriate cytocompatibility for cartilage tissue engineering applications. Furthermore, an in vivo study indicated that the formation of a healthy hyaline cartilage after the microfracture was enhanced by the fabricated hydrogel implant, offering a potential biocompatible platform for microfracture-based cartilage reconstructive surgery.

No abstract

The cell-derived extracellular matrix (ECM) is associated with a lower risk of pathogen transfer, and it possesses an ideal niche with growth factors and complex fibrillar proteins for cell attachment and growth. However, the cell-derived ECM is found to have poor biomechanical properties, and processing of cell-derived ECM into gels is scarcely studied. The gel provides platforms for three-dimensional cell culture, as well as injectable biomaterials, which could be delivered via a minimally invasive procedure. Thus, in this study, an adipose-derived stem cell (ADSC)-derived ECM gel was developed and cross-linked by genipin to address the aforementioned issue. The genipin cross-linked ADSC ECM gel was fabricated via several steps, including rabbit ADSC culture, cell sheets, decellularization, freeze–thawing, enzymatic digestion, neutralization of pH, and cross-linking. The physicochemical characteristics and cytocompatibility of the gel were evaluated. The results demonstrated that the genipin cross-linking could significantly enhance the mechanical properties of the ADSC ECM gel. Furthermore, the ADSC ECM was found to contain collagen, fibronectin, biglycan, and transforming growth factor (TGF)-β1, which could substantially maintain ADSC, skin, and ligament fibroblast cell proliferation. This cell-derived natural material could be suitable for future regenerative medicine and tissue engineering application.