Novel Hydroxypropyl Methyl Cellulose-based Hydrogels for Tissue Engineering Applications

Introduction

Tissue engineering, which is the development of biological substitutes to replace or repair damaged tissues or organs, has been identified as one of the most promising solutions to overcome the shortage of donor organs and tissues. Hydrogels are one of the most widely used materials in tissue engineering, due to their excellent properties such as biocompatibility, permeability, and mechanical properties similar to living tissues. Hydroxypropyl methyl cellulose (HPMC) is a biocompatible and biodegradable material that has the potential to be used as a hydrogel for tissue engineering applications. This review aims to highlight the recent development and potential applications of HPMC-based hydrogels for tissue engineering.

Hydroxypropyl Methyl Cellulose

HPMC is a derivative of cellulose that is produced by the chemical modification of cellulose with propylene oxide and methyl chloride. It is a hydrophilic polymer that is soluble in water and can form a gel at room temperature when it is crosslinked. The properties of HPMC can be manipulated by adjusting the degree of substitution (DS) and degree of polymerization (DP), which affects the molecular weight and the extent of crosslinking.

HPMC-Based Hydrogels

HPMC-based hydrogels have attracted attention in the field of tissue engineering due to their biocompatibility, biodegradability, and ability to regulate cell behavior. HPMC can be crosslinked by various crosslinking agents, such as glutaraldehyde, genipin, and carbodiimide, to form hydrogels. The mechanical properties of HPMC-based hydrogels can be tuned by varying the degree of crosslinking and the concentration of HPMC. The swelling ratio and degradation rate of HPMC-based hydrogels can also be controlled by changing the DS and DP of HPMC.

Besides, HPMC is a versatile material that can be combined with other natural or synthetic polymers to form composite hydrogels. For example, HPMC has been blended with gelatin, chitosan, and polyethylene glycol (PEG) to form composite hydrogels with improved mechanical properties and biocompatibility.

Applications of HPMC-Based Hydrogels in Tissue Engineering

Hydrogels based on HPMC have been widely investigated for a broad range of tissue engineering applications, including bone, cartilage, skin, and drug delivery.

Bone Tissue Engineering

Several studies have demonstrated the potential of HPMC-based hydrogels for bone tissue engineering. It has been reported that HPMC hydrogels can support the attachment, proliferation, and differentiation of osteoblasts, the cells responsible for bone formation. Furthermore, the incorporation of hydroxyapatite (HA), a mineral that is naturally found in bone tissue, into HPMC hydrogels can improve the mechanical strength and mineralization of the hydrogels. A study shows that HPMC/HA composite hydrogels with a suitable composition can induce the differentiation of mesenchymal stem cells into osteoblasts and promote bone regeneration in a rat skull defect model.

Cartilage Tissue Engineering

Hydrogels based on HPMC have also been explored for cartilage tissue engineering. Due to its unique properties such as high water content and viscoelasticity, HPMC hydrogels can mimic the microenvironment of native cartilage. Several studies have demonstrated that HPMC hydrogels can support the growth and differentiation of chondrocytes, the cells responsible for producing and maintaining cartilage. Moreover, the mechanical properties of HPMC-based hydrogels can be improved by incorporating other natural or synthetic polymers, such as gelatin and PEG, which can mimic the structure of native cartilage.

Skin Tissue Engineering

HPMC-based hydrogels have also been investigated for skin tissue engineering applications. It has been reported that HPMC hydrogels can support the growth and differentiation of human skin cells, including keratinocytes and fibroblasts. Furthermore, HPMC hydrogels can enhance the expression of genes related to extracellular matrix production and tissue remodeling, indicating their potential for promoting skin regeneration.

Drug Delivery

HPMC-based hydrogels have also been explored as drug delivery systems due to their ability to encapsulate drugs and release them in a sustained manner. HPMC hydrogels can be easily fabricated into various forms, such as films, beads, and nanoparticles, which can be utilized for the delivery of different types of drugs, including small molecules, peptides, and proteins. Several studies have demonstrated the ability of HPMC hydrogels to sustain the release of drugs for an extended period of time, which can reduce the frequency of drug administration and improve patient compliance.

Conclusion

In conclusion, HPMC-based hydrogels have shown great promise in tissue engineering applications due to their unique properties, such as biocompatibility, biodegradability, and tunable mechanical properties. HPMC hydrogels can be easily fabricated into various forms and can be combined with other natural or synthetic polymers to form composite hydrogels with synergistic properties. Future research should focus on optimizing the properties of HPMC hydrogels and investigating their efficacy in in vivo models. With continued advancements in HPMC-based hydrogels, it is expected that it will have a significant impact on tissue engineering and regenerative medicine in the future.