Thermosensitive Chitosan-β-Glycerophosphate Hydrogels as Targeted Drug Delivery Systems: An Overview on Preparation and Their Applications

Table 1

Type of thermo-responsive hydrogels.

	Polymers combined with	Gelling temperature °C	In the market	Disadvantages	Advantages	Application	Reference
1. Cellulose derivative
1.1 methylcellulose	N-isopropyl acrylamide (NiPAAM)	60–80				Create a bioactive scaffold	[14]
1.2 chitosan	PEG [15]; N-isopropyl acrylamide (NiPAAM) [16]; Glycerophosphate [17]	37	BST-Gel ® [18]	The initial release of the drug is high.; It always retains some of the drugs.; It has a low rate of destruction	Forms a reversible gel that gels when placed in the body.; It can release the drug for a long time. Biodegradable and good biocompatibility	Cell delivery; Drug delivery; Implant; Similar structure to extracellular matrix	[17]
1.3 Dextran	N-isopropyl acrylamide (NiPAAM)	32–37		At a temperature of 37 degrees, its degradation rate decreases.; Drug release depends on various factors such as pH and electrolyte	It can create a sustained release formulation	Drug delivery	[19]
2. Proteins
2.1 Gelatine	Poly(ethylene glycol)-Poly (D, L-lactic); (mPEG-DLLA) [20]	Below 25		Improper gelling and adhesion properties; The initial release of the drug is high	Slow-release profile	Drug release kinetic with gentamycin sulfate	[21]
Other polymers
3. N-isopropylacrylamide		32		Nonbiodegradable; The gelling temperature depends on the pH and electrolytes of the environment.; Swelling was lower; Initial burst release	Preparation of implants; Long-term drug release	Drug delivery; Cell encapsulation; Cell culture; Biomedical engineering application	[22]
4. PEO/PPO; Poloxamer ®	Poly (ether-carbonate)	37	LeGoo ® [23]	Lower stiffness than other hydrogels; After one week degraded	Biocompatible; High viscosity	Drug and gene delivery; Tissue adhesive; Burn wound covering	[24, 25]