Development of plant-based biopolymer coatings for 3D cell culture: boron-silica-enriched quince seed mucilage nanocomposites

Spheroid formation with spontaneous aggregation has captured interest in most cell culture studies due to its easy set-up and more reliable results. However, the economic and technical costs of the advanced systems and commercial ultra-low adhesive platforms have pushed researchers into pursuing alternatives. Nowadays, polymeric coatings, including poly-hydroxyethyl methacrylate and agar/agarose, are the commonly used polymers for non-adhesive plate fabrication, yet the costs and working solvent or heat-dependent preparation procedures maintain the need for the development of novel biomaterials. Here, we propose a greener and more economical approach for producing non-adherent surfaces and spheroid formation. For this, a plant waste-based biopolymer from quince fruit (Cydonia oblonga Miller, from Rosaceae family) seeds and boron-silica precursors were introduced. The unique water-holding capacity of quince seed mucilage (Q) was enriched with silanol and borate groups to form bioactive and hydrophilic nanocomposite overlays for spheroid studies. Moreover, 3D gel plates from the nanocomposite material were fabricated and tested in vitro as a proof-of-concept. The surface properties of coatings and the biochemical and mechanical properties of the nanocomposite materials were evaluated in-depth with techniques, and extra hydrophilic coatings were obtained. Three different cell lines were cultured on these nanocomposite surfaces, and spheroid formation with increased cellular viability was recorded on day 3 with a >200 μm spheroid size. Overall, Q-based nanocomposites are believed to be a fantastic alternative for non-adherent surface fabrication due to their low-cost, easy operation, and intrinsic hydration layer forming capacity with biocompatible nature in vitro.

Nano-hydroxyapatite incorporated quince seed mucilage bioscaffolds for osteogenic differentiation of human adipose-derived mesenchymal stem cells

In this study, the therapeutic hydrocolloid quince seed mucilage (QSM) from Cydonia oblonga Miller fruit is enriched with needle-like nano-hydroxyapatite (nHAp) crystals to fabricate a novel biomimetic osteogenic bioscaffold. The molecular weight (M_w) of water-based extracted QSM was measured with GPC (8.67 × 10⁵ g/mol), and the composite blend was prepared at a ratio of 1:1 (w/w) QSM_aq and nHAp. The porous bioscaffolds were manufactured by the freeze-drying method, and evaluated in-depth with advanced analyses. The XRD, ATR-FTIR, SEM-EDX, and elemental mapping analyses revealed a uniform coated semi-crystalline structure with no covalent bindings between QSM and nHAp. Moreover, due to the hydrocolloid backbone, a supreme swelling ratio (w/w, 6523 ± 190%) with suitable pore size (208.12 ± 99.22 μm) for osteogenic development was obtained. Further, the cytocompatible bioscaffolds were evaluated for osteogenic differentiation in vitro using human adipose-derived mesenchymal stem cells (hAMSCs). The immuno/histochemical (I/HC) staining revealed that the cells with the spherical morphology invaded the pores of the prepared bioscaffolds. Also, relatively early up-regulated osteogenic markers were observed by the qRT-PCR analyses. Overall, it is believed that the QSM-nHAp bioscaffolds might be favorable in non-load bearing applications, especially in the cranio-maxillofacial region, due to their regenerative, bendable, and durable features.

From a plant secretion to the promising bone grafts: Cryogels of silicon-integrated quince seed mucilage by microwave-assisted sol-gel reaction

Design and fabrication of biologically active cryogels using novel biopolymer(s) are still of great importance at regenerating bone defects such as traumatic bone injuries, maxillofacial surgery, osteomyelitis, and osteoporosis. Nowadays, plant mucilage, an herbal biomaterial, has been drawn attention by scientists due to their marvelous potential to fabricate 3-dimensional (3D) physical constructs for the field of regenerative medicine. Herein, a 3D cryogel from silicon-integrated quince seed mucilage (QSM) is constructed using microwave-assisted sol-gel reaction, characterized in-depth by attenuated total reflectance Fourier transform-infrared spectroscopy (ATR-FTIR), solid-state silicon cross-polarization magic-angle nuclear magnetic resonance (²⁹Si-CP-MAS NMR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), micro-mechanical testing, porosity, and swelling tests, contact angle measurements, Brunauer-Emmet-Teller and Barret-Joyner-Halenda (BET-BJH) analysis, enzymatic biodegradation test, and field emission-scanning electron microscopy-energy dispersive X-ray spectroscopy (FE-SEM-EDX) mapping. The osteobiologic capacity of the cryogels is determined using human adipose-derived mesenchymal stem cells (hAMSCs) under in vitro conditions. Osteogenic differentiation of hAMSCs on both QSM and silica-modified QSM (Si-QSM) cryogels is analyzed by histochemistry, immunohistochemistry, and quantitative-real time (q-RT) PCR techniques. The results obtained from in vitro experiments demonstrate that the upregulation of osteogenesis-related genes in Si-QSM cryogels presents a stronger and earlier development over QSM cryogels throughout the culture period, which in turn reveals the great potential of this novel Si-incorporated QSM cryogels for bone tissue engineering applications.