3 minute read
Adaeze Eze
Adaeze Eze
Naznin Sultana Texas Undergraduate Medical Academy
Introduction: Tissue engineering or tissue regeneration associates living cells with biodegradable materials and/or bioactive components. Composite scaffolds containing biodegradable polymers with suitable properties are promising for controlled release drug delivery and tissue regeneration. Chitosan is a natural polysaccharide that is non-toxic, biocompatible and biodegradable and hence is promising to use as scaffold material in bone tissue engineering. On the other hand, Pectin gels are extensively used in biomedical applications due to their easily tunable physical properties, high water association capacity and ability to act as carrier of proteins, drugs or cells. There are several techniques to fabricate membranes or scaffolds from polymer solutions. Thermally induced phase separation (TIPS) and freeze-drying technique is another promising technique to produce 3-D scaffolds (Sultana and Wang, 2008; Sultana and Wang, 2012). The need for synthetic tissue with similar biological and chemical properties to natural tissue has increased due to the limited availability of natural tissue grafts. This limitation is the main motivation for developing artificial composite materials. Tissue engineering has provided a new approach for treating various tissue ailments. Therefore, recent research has focused on biodegradable natural polymers based composite scaffolds as an alternative strategy to remediate skin regeneration. The hypothesis of this research is that the Chitosan/pectin- based scaffold can be successfully applied to regenerate skin tissue. The specific aims of the project is: (1) To fabricate Chitosan/Pectin scaffolds. We will use the TIPS and freeze-drying technique to prepare a nanofibrous scaffold with Chitosan/Pectin. (2) To characterize the physical, chemical and biological properties of scaffolds. We will evaluate morphopholy, porosity, and cytotoxicity using human skin fibroblasts. Materials and Methods: Chitosan with medium molecular weight and pectin from a citrus peel (Pc, galacturonic acid content of 80.2%, methoxylation degree of 7.6% and M, of 45kDa) were purchased from Sigma-Aldrich. The fabrication technique was described previously (Eze et al., 2020). The amount of pectin added was 0.05g and 0.1 g, respectively. The morphology of a small section of each sample is examined by SEM (Hitachi TM3000, Japan) at an accelerating voltage of 15 kV (Chung, 2016) to confirm the morphology. Results and Discussion: Recent studies have placed a focus on the polymer, pectin, due to its inexpensive cost combined with its biological properties that enables it to be used in various applications such as pharmacological and food applications. Pectins make up an essential part that is needed for the development of plants. The polymer helps to provide intercellular adhesion, rigidity, turgidity, and mechanical resistance for the cell walls of plants. The multifunctional component of pectin has allowed it to provide numerous target sites for chemical modifications (Pereira et al., 2018). The properties of pectin such as its non-toxicity, emulsion behavior, diverse chemical composition, biocompatibility, and high stability, enables it to be a commonly used polymer. Industrially, pectin is used for various types of applications such as food manufacturing, drug delivery, and tissue engineering. Porous pectin and Chitosan based tissue scaffolds were successfully fabricated using a freeze-drying technique and evaluated for different required properties (Figure 1).
Figure 1: In-lab activities of preparation of pectin/chitosan scaffolds and characterization
Conclusion(s) or Summary: A thorough literature review was documented and will be submitted to publish as a review article which proved that pectin can act as a non-toxic constituent, gelling agent, and insoluble substance that can be used as tissue regeneration and drug delivery applications. The first aim of this project was successfully achieved. Further study on cell culture is needed to confirm the cytotoxicity of chitosan-pectin composite scaffolds to achieve the second aim. References: Sultana N, Wang M. 2008. Fabrication of HA/PHBV composite scaffolds through the emulsion freezing/freeze-drying process and characterisation of the scaffolds. J Mater Sci Mater Med 19: 2555-2561. Sultana N, Wang M. 2012. PHBV/PLLA-based composite scaffolds fabricated using an emulsion freezing/freeze-drying technique for bone tissue engineering: surface modification and in vitro biological evaluation. Biofabrication. 2012;4:015003 Pereira, F. R., Barrias C. C., Bartolo, J. P., & Granja L. P. (2018). Cell-instructive pectin hydrogels crosslinked via thiol-norbornene photo-click chemistry for skin tissue engineering. Acta Biomaterialia, 282293. https://doi.org/10.1016/j.actbio.2017.11.016
