Preparation and Characterization of Salt-Mediated Injectable Thermosensitive Chitosan/Pectin Hydrogels for Cell Embedding and Culturing

Abstract

In recent years, growing attention has been directed to the development of 3D in vitro tissue models for the study of the physiopathological mechanisms behind organ functioning and diseases. Hydrogels, acting as 3D supporting architectures, allow cells to organize spatially more closely to what they physiologically experience in vivo. In this scenario, natural polymer hybrid hydrogels display marked biocompatibility and versatility, representing valid biomaterials for 3D in vitro studies. Here, thermosensitive injectable hydrogels constituted by chitosan and pectin were designed. We exploited the feature of chitosan to thermally undergo sol–gel transition upon the addition of salts, forming a compound that incorporates pectin into a semi-interpenetrating polymer network (semi-IPN). Three salt solutions were tested, namely, beta-glycerophosphate (βGP), phosphate buffer (PB) and sodium hydrogen carbonate (SHC). The hydrogel formulations (i) were injectable at room temperature, (ii) gelled at 37 °C and (iii) presented a physiological pH, suitable for cell encapsulation. Hydrogels were stable in culture conditions, were able to retain a high water amount and displayed an open and highly interconnected porosity and suitable mechanical properties, with Young’s modulus values in the range of soft biological tissues. The developed chitosan/pectin system can be successfully used as a 3D in vitro platform for studying tissue physiopathology.

The Evolution of Technology‐Driven In Vitro Models for Neurodegenerative Diseases

“…Both polymers are widely used in the biomedical field as they are characterized by high biocompatibility, biodegradability, low toxicity, adhesive properties, and antibacterial properties. [ 93 ] Alginate is an algae‐derived polymer, readily available at low cost and one of the most widely used polymers for 3D culture systems. Alginate hydrogels are crosslinked in various ways and mimic many of the natural characteristics of the ECM.…”

“…By fusing together these two approaches, it is possible to overcome the drawbacks inherent each technique, achieving better results. [ 158 ] There are three main possibilities: [ 74–159 ] i) manufacturing the mold through 3D printing, casting PDMS on 3D templates; ii) printing hydrogel‐embedded cells in a pre‐fabricated device; and iii) printing the entire chip device, including both cells and templates (i.e., microfluidic channels).…”

Modern Wound Dressings: Hydrogel Dressings

“…Hydrogels with a purely physical mechanism of gelation do not require the introduction of additional functional groups for polymerization, but they are characterized by weak viscoelastic properties [ 36 , 37 ], which are difficult to control. Even though hydrogels with physical gelation are pseudoplastic, their use is limited to applications not associated with deformation loads such as, for example, an injection hydrogel [ 38 ]. It should be noted that hydrogel dressings routinely used in clinical practice have a physical mechanism of gelation or consist of interpenetrating polymer networks (for example,; Helix3 cm-highly porous flat sheets of type I collagen; Algisite M - calcium alginate dressing) [ 39 ].…”

Biomaterials for Regenerative Medicine in Italy: Brief State of the Art of the Principal Research Centers

“…In fact, 3D printing is a powerful technique that allows the precise and controlled deposition of biomaterials in a predesigned and reproducible manner. Furthermore, specific features of hydrogels allow for the creation of a thermo-sensitive system suitable for cell embedding and culturing and to obtain a bubble-free system with optimal chemical-physical characteristics for 3D culture systems [ 7 ].…”