Preparation and In Vitro Evaluation of Chitosan-g-Oligolactide Based Films and Macroporous Hydrogels for Tissue Engineering

Abstract

In the current study, novel matrices based on chitosan-g-oligo (L,L-/L,D-lactide) copolymers were fabricated. In particular, 2D films were prepared by solvent casting, while 3D macroporous hydrogels were obtained by lyophilization of copolymer solutions. Copolymers of chitosan (Chit) with semi-crystalline oligo (L,L-lactide) (Chit-LL) or amorphous oligo (L,D-lactide) (Chit-LD) were obtained by solid-state mechanochemical synthesis. The structure of the hydrogels was found to be a system of interconnected macropores with an average size of 150 μm. In vitro degradation of these copolymer-based matrices was shown to increase in the case of the Chit-LL-based hydrogel by 34% and decrease for the Chit-LD-based hydrogel by 23% compared to the parameter of the Chit sample. Localization and distribution of mouse fibroblast L929 cells and adipose tissue-derived mesenchymal stromal cells (MSCs) within the hydrogels was studied by confocal laser scanning microscopy (CLSM). Moreover, cellular response, namely cell adhesion, spreading, growth, proliferation, as well as cell differentiation in vitro were also evaluated in the hydrogels for 10–14 days. Both the Chit-LL and Chit-LD matrices were shown to support cell growth and proliferation, while they had improved swelling compared to the Chit matrix. Osteogenic MSCs differentiation on the copolymer-based films was studied by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). Maximal expression levels of osteogenesis markers (alkaline phosphatase (ALPL), bone transcription factor (Runx2), and osteopontin (SPP1) were revealed for the Chit-LD films. Thus, osteodifferentiation was demonstrated to depend on the film composition. Both Chit-LL and Chit-LD copolymer-based matrices are promising for tissue engineering.

Composite Hydrogels Based on Cross-Linked Chitosan and Low Molecular Weight Hyaluronic Acid for Tissue Engineering

“…In addition, swelling properties could affect degradation rate. Earlier, the degradation rate was shown to increase along with swelling degree enhancement [ 39 , 40 ]. Moreover, the mechanical properties of wet hydrogels were found to be significantly reduced [ 9 , 22 ], which could negatively affect cell adhesion, morphology and proliferation.…”

Porous Chitosan Hydrogels Produced by Physical Crosslinking: Physicochemical, Structural, and Cytotoxic Properties

“…The polymer structure expands as the hydrogel hydrates, increasing the pore size. Tolstova et al [44] reported similar mean pore size (150 ± 5 µm) for chitosan hydrogels produced by the freeze-drying and thermal crosslinking process (150 • C for 5 h). The authors used fluorescamine as amino-specific staining to observe the macrostructure of chitosan hydrogels.…”

“…For example, Azueta-Aguayo et al [25] described that pore sizes of about 100 µm are suitable for cell proliferation. In addition, the interconnected porous structures, and the high degree of porosity of the scaffolds can provide good nutrient and oxygen transfer, resulting in improved cell migration and ECM production inside the scaffolds [8,44].…”

Novel polymer-based hydrogels of recent research in drug delivery for disease treatment related to SARS-CoV-2 virus

“…Hydrogels can be categorized based on their pore size, which determines their permeability and ability to accommodate different-sized molecules or cells. This classification includes macroporous hydrogels [144], mesoporous hydrogels [145], and microporous hydrogels [146]. Hydrogels can be classified based on their physical appearance, such as transparent hydrogels [147], opaque hydrogels, or hydrogel films [45].…”