ABSTRACT Hydrogels have been widely used in many applications from tissue engineering to drug delivery systems. For both tissue engineering and drug delivery, the mechanical properties are important because they would affect cell-materials interactions and injectability of drugs encapsulated in hydrogel carriers. Therefore, it is important to study the mechanical properties of these hydrogels, particularly at physiological temperature (37°C). This study adopted strain sweep and frequency sweep rotational rheological tests to investigate the rheological characteristics of various tissue engineering relevant hydrogels with different concentrations at 37°C. These hydrogels include alginate, RGD-alginate, and copolymerized collagen/alginate/fibrin. It has revealed that the addition of RGD has negligible effect on the elastic modulus and viscosity of alginate. Alginate gels have demonstrated shear thinning behavior which indicates that they are suitable candidates as carriers for cells or drug delivery. The addition of collagen and fibrin would reinforce the mechanical properties of alginate which makes it a strong scaffold material.
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Recent Progress in Biopolymer-Based Hydrogel Materials for Biomedical Applications
Hydrogels from biopolymers are readily synthesized, can possess various characteristics for different applications, and have been widely used in biomedicine to help with patient treatments and outcomes. Polysaccharides, polypeptides, and nucleic acids can be produced into hydrogels, each for unique purposes depending on their qualities. Examples of polypeptide hydrogels include collagen, gelatin, and elastin, and polysaccharide hydrogels include alginate, cellulose, and glycosaminoglycan. Many different theories have been formulated to research hydrogels, which include Flory-Rehner theory, Rubber Elasticity Theory, and the calculation of porosity and pore size. All these theories take into consideration enthalpy, entropy, and other thermodynamic variables so that the structure and pore sizes of hydrogels can be formulated. Hydrogels can be fabricated in a straightforward process using a homogeneous mixture of different chemicals, depending on the intended purpose of the gel. Different types of hydrogels exist which include pH-sensitive gels, thermogels, electro-sensitive gels, and light-sensitive gels and each has its unique biomedical applications including structural capabilities, regenerative repair, or drug delivery. Major biopolymer-based hydrogels used for cell delivery include encapsulated skeletal muscle cells, osteochondral muscle cells, and stem cells being delivered to desired locations for tissue regeneration. Some examples of hydrogels used for drug and biomolecule delivery include insulin encapsulated hydrogels and hydrogels that encompass cancer drugs for desired controlled release. This review summarizes these newly developed biopolymer-based hydrogel materials that have been mainly made since 2015 and have shown to work and present more avenues for advanced medical applications.
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- Award ID(s):
- 1809541
- PAR ID:
- 10377440
- Date Published:
- Journal Name:
- International Journal of Molecular Sciences
- Volume:
- 23
- Issue:
- 3
- ISSN:
- 1422-0067
- Page Range / eLocation ID:
- 1415
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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