Chondroitin Sulfate-Based Cryogels for Biomedical Applications

Abstract

Cryogels attained from natural materials offer exceptional properties in applications such as tissue engineering. Moreover, Halloysite Nanotubes (HNT) at 1:0.5 weight ratio were embedded into CS cryogels to render additional biomedical properties. The hemolysis index of CS cryogel and CS:HNT cryogels was calculated as 0.77 ± 0.41 and 0.81 ± 0.24 and defined as non-hemolytic materials. However, the blood coagulation indices of CS cryogel and CS:HNT cryogels were determined as 76 ± 2% and 68 ± 3%, suggesting a mild blood clotting capability. The maximum% swelling capacity of CS cryogel was measured as 3587 ± 186%, 4014 ± 184%, and 3984 ± 113%, at pH 1.0, pH 7.4 and pH 9.0, respectively, which were reduced to 1961 ± 288%, 2816 ± 192, 2405 ± 73%, respectively, for CS:HNT cryogel. It was found that CS cryogels can hydrolytically be degraded 41 ± 1% (by wt) in 16-day incubation, whereas the CS:HNT cryogels degraded by 30 ± 1 wt %. There is no chelation for HNT and 67.5 ± 1% Cu(II) chelation for linear CS was measured. On the other hand, the CS cryogel and CS:HNT cryogel revealed Cu(II) chelating capabilities of 60.1 ± 12.5%, and 43.2 ± 17.5%, respectively, from 0.1 mg/mL Cu(II) ion stock solution. Additionally, at 0.5 mg/mL CS, CS:HNT, and HNT, the Fe(II) chelation capacity of 99.7 ± 0.6, 86.2 ± 4.7% and only 11.9 ± 4.5% were measured, respectively, while no Fe(II) was chelated by linear CS chelated Fe(II). As the adjustable and controllable swelling properties of cryogels are important parameters in biomedical applications, the swelling properties of CS cryogels, at different solution pHs, e.g., at the solution pHs of 1.0, 7.4 and 9.0, were measured as 3587 ± 186%, 4014 ± 184%, and 3984 ± 113%, respectively, and the maximum selling% values of CS:HNT cryogels were determined as 1961 ± 288%, 2816 ± 192, 2405 ± 73%, respectively, at the same conditions. Alpha glucosidase enzyme interactions were investigated and found that CS-based cryogels can stimulate this enzyme at any CS formulation.

Enhanced Bioactive Properties of Halloysite Nanotubes via Polydopamine Coating

“…It is known in the literature that HNTs inhibit the AG enzyme [ 57 ]. Here, the AG enzyme inhibition ability of PDOPA@HNT was also studied, and we compared the neat HNTs with PDOPA@HNTs at the same concentration (2.0 mg/mL).…”

Polyelectrolyte Chondroitin Sulfate Microgels as a Carrier Material for Rosmarinic Acid and Their Antioxidant Ability

“…Some polymers provide an iron-chelating ability and can be used to inhibit iron toxication in the body [ 38 ]. The Fe(II)-chelating capacities of CS microgels and CS − [R] + microgels were examined in a DI water solution in the 125–2000 µg/mL concentration range in accordance with the literature [ 37 ]. In our previous work, the Fe(II) chelation ability of CS was not observed, even at a 2000 μg/mL concentration.…”

“…In accordance with the literature, CS microgel and CS − [R] + microgel aqueous solutions were prepared at 2000 µg/mL concentrations and were diluted to 1000, 500, 250, and 125 µg/mL. Then, 140 µL of CS microgel or CS − [R] + microgel suspension solution was added into 96 wells [ 37 ]. Then, 20 µL of 1 mM Fe (II) aqueous solution was added to them, and measurements were obtained using a microplate reader (Thermo Multiskan Go, USA) at 562 nm.…”

Macroporous Cell-Laden Gelatin/Hyaluronic Acid/Chondroitin Sulfate Cryogels for Engineered Tissue Constructs

“…When comparing hydrogels and cryogels, hydrogels are crosslinked 3D networks with a high water content [ 9 , 10 ]. Hydrogels are known to swell better than cryogels, however; Hixon et al synthesized silk fibrin cryogels and hydrogels and showed that cryogels can swell to a greater extent [ 11 , 12 , 13 ]. Cryogels, on the other hand, have such important properties as flexibility, large pores, high mechanical strength, short diffusion paths and good biocompatibility [ 14 , 15 ].…”

“…Cryogels can also have shape-memory properties and can be synthesized in various forms, such as powder, columns, beads, membranes, monoliths, and injectable forms [ 16 , 17 , 18 , 19 , 20 , 21 ]. The high porosity makes them suitable for use as macroporous cell-laden scaffolds for tissue constructions [ 13 ]. These cryogels can be used in a variety of biomedical applications, including diagnostics, therapeutics, drug delivery and tissue engineering.…”