Study Of Drug-loaded Collagen/Polyethylene Glycol-diacrylate Composite Hydrogels

Scleral incision operation is usually needed in ophthalmic surgery.Postoperative suturing of the incision can inevitably increase the complexity of the operation,which leads to infected patients.Moreover,a large amount of intravenous infusion and ophthalmic preparation are needed to eliminate the infection afterwards.Therefore,it is necessary to develop a scaffold material for ophthalmic surgery,which can replace the suturing process and avoid eye infection.Collagen is the main structural component of the extracellular matrix,with excellent biocompatibility,low antigenicity,high degradability and good hemostatic properties to promote cell growth and migration.Polyethylene glycol diacrylate(PEGDA)is a derivative of polyethylene glycol(PEG),with features of biologically non-toxic,excellent biocompatibility and biodegradability.In this study,a drug-loaded collagen/polyethylene glycol diacrylate composite hydrogel was prepared,which is proposed to be used instead of the suturing process.In addition,the antibacterial drug in hydrogel might be continuously released to promote the healing of ocular incision.Therefore,the prepared hydrogels herein have potential applications value in ophthalmic surgery.Polycaprolactone-polyethylene glycol-polycaprolactone(PCEC)amphiphilic triblock copolymer was prepared by a ring-opening polymerization method.The drug-loaded microspheres were then prepared with PCEC and antibacterial levofloxacin by a thin film dispersion method.The effects of different molecular weight of PEG(Mn=1500,2000,4000,10000)on particle size,drug loading and encapsulation efficiency of drug-loaded microspheres were investigated as well.Results show that at the Mn of 2000,the drug-loaded microspheres have the best performance with a regular spherical shape and a particle size of 41.49 nm_The drug loading and encapsulation efficiency are 9.76±1.18%and 96.90±1.17%,respectively.The PEGDA was synthesized with PEG and acryloyl chloride,and then PEGDA hydrogels were prepared with different molecular weights of PEGDA.The effects of different molecular weights of PEGDA(PEGDA(200),PEGDA(400),PEG(2k)DA,PEG(4k)DA,PEG(10k)DA)on the morphology,compressive properties and swelling ratios of hydrogels were investigated.Results show that with the increases of molecular weight of PEGDA,the compressive strength and the swelling ratios of PEGDA hydrogels increase.However,the internal structure of PEGDA hydrogel is dense with few pores,indicating that PEGDA hydrogel is not suitable as a scaffold material.The modified collagen(CGMA)with C=C was obtained by grafting collagen with gycidyl methacrylate(GMA).The CGMA/PEGDA hydrogels were prepared with CGMA and PEGDA.The effects of PEGDA molecular weight and CGMA concentration on morphology,compressive properties,swelling ratios,in vitro degradation ratios and cytotoxicity of hydrogels were investigated,with the results that the hydrogels from PEG(10k)DA have better performance than others.The introduction of CGMA improves pore structure and compressive strength of PEGDA hydrogel.As the concentration of CGMA increases,the degradation ratio of hydrogel also increases,but the swelling ratio decreases.Cytotoxicity tests suggests a good biocompatibility for CGMA/PEGDA hydrogels.The CGMA/PEGDA composite hydrogel is still not fully degraded in vitro after two months,which might provide a long-term support for surgical incision healing.The CGMA/PEGDA hydrogel is expected to be used as a scaffold material in ophthalmic surgery.The drug-loaded CGMA/PEGDA hydrogel was prepared by drug-loaded microsphere,CGMA and PEGDA.In vitro release,antibacterial properties and cytotoxicity of drug-loaded CGMA/PEGDA hydrogel were studied.The results show that the hydrogel has a good sustained release effect,anti-E.coli effect and biocompatibility.The drug-loaded CGMA/PEGDA hydrogel is expected to provide a suitable environment for surgical incision healing.