# Biomedical Applications of Polymeric Cryogels
## 3 Cryogels in Medical Applications
### Cryogels for Tissue Engineering
#### 3.4.4 Other Tissue Engineering Applications  
Cardiovascular grafts usage has not been appropriate because of donor availability. If there is a treatment process, patients can be faced with such risk factors including hyperplasia, calcification and inflammation. In addition, using heart valves brings along with some challenges in terms of degeneration in the time period and calcification. Therefore, cryogels have been received attention for these applications. In a previous study, (PVA)-gelatin cryogels were preferred as an alternative to arterial grafts due to their mechanical usefulness. It was indicated that (PVA)-gelatin cryogels were applicable for the arterial endothelialization under shear stress leading high nitric oxide (NO) levels [94]. A different study reported alginate-based cryogels seeded with rat embryo cells have promoted angiogenesis and ECM formation when they were implanted into rats. Furthermore, these findings were supported in pigs [95]. Intervertebral disc problems could be occurred when the discs were damaged resulting in prolonged pressure, lowered vascularization, degenerative diseases. Cryogel applications have become an alternative to spinal surgery. In a study, PVA cryogels were applied by their ability to mimic artificial lumbar intervertebral disc with the advantage of their mechanical property. Optimization experiments were performed, and it was shown that compressive stress relaxation and creep levels decreased in high levels of PVA [96]. In another studies, silk fibroin incorporated PVA cryogels were constructed to enhance biocompatibility and gelatin-poloxamer 407 biocomposite cryogel were produced to extend water retention [97]. Another field of cryogel usage is neural cell adhesion. In a study, incorporated laminin gelatin/dextran cryogels were examined and it was reported that laminin supported cell attachment \begin{table}
\begin{tabular}{c c c} \hline \hline
**Scaffolds** & **Outcome** & **Reference** \\ \hline \multirow{6}{*}{Collagenase incorporated cryogel} & Cartilage & \\  & Isolation of chondrocytes and triggered proliferation in a & \\  & sheep model & [71] \\  & Synthesis of type II collagen & \\  & 2-hydroxyethyl & Verification of biocompatibility with cartilage cells & \\  & methacrylate–lactate–dextran & Chondrocyte attachment and infiltration & [84] \\  & (HEMA-ALA-D)-based cryogels & 73.7 \(\pm\) 3.3\% cell viability after 15 days & \\  & Chitosan-gelatin cryogels & & \\  & incorporated with chondro & Encouraged chondrocyte reproduction and differentiation & [85] \\  & sulfate loaded microparticles & Elevated matrix formation & [86] \\  & Gelatin-oxidized dextran cryogels & & \\  & with bone morphogenetic & Improved matrix synthesis & [86] \\  & protein-7 (BMP-7) & & \\  & Chitosan-agarose-gelatin cryogels & & \\  & & \\  & Biomimetic & & \\  & gelatin/chondroitin-6-sulfate/ & Up-regulation of glycosaminoglycans (GAGs) and type II & [88] \\  & hyaluron cryogel incorporated & collagen (COL II) secretion & [88] \\  & with chitosan & Skin & \\  & Fibrinogen and gelatin containing & High migration of human dermal fibroblast by elevated & [89] \\  & cryogels & fibrinogen concentration & \\  & Gelatin-fibrinogen cryogel & & \\  & & & \\  & Chitosan-gluconic acid & High infiltration of inflammatory cells into wound & \\  & conjugate/poly(vinyl alcohol) & In vivo: Healing of partial-thickness wounds with incorporation & [91] \\  & cryogels & of basic fibroblast growth factor & \\  & Keratinase and enrofloxacin & & \\  & loaded pectin PVA cryogel & Controllable release of antibiotics & [92] \\  & Bilayer cryogels, & & \\  & Top layer: antiseptic layer & Cell infiltration and attachment & \\  & Polyvinylpyrrolidone-iodine (PVP-I) & Proliferation of fibroblasts and keratinocytes & [93] \\  & Bottom layer: regenerative layer & In vivo: Regeneration ability was proven in implanted rabbits & \\  & Gelatin cryogel & Resembling to commercial skin regeneration product Neuskin-F & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: _Cont._and movement of neurons.