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To improve the efficacy of anti-inflammatory factors in patients who undergo cataract surgery, poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) (p(HEMA-co-MMA)) hydrogels containing β-cyclodextrin (β-CD) (pHEMA/MMA/β-CD) were designed and prepared as intraocular lens (IOLs) biomaterials that could be loaded with and achieve the sustained release of dexamethasone. A series of pHEMA/MMA/β-CD copolymers containing different ratios of β-CD (range, 2.77 to 10.24 wt.%) were obtained using thermal polymerization. The polymers had high transmittance at visible wavelengths and good biocompatibility with mouse connective tissue fibroblasts. Drug loading and release studies demonstrated that introducing β-CD into hydrogels increased loading efficiency and achieved the sustained release of the drug. Administering β-CD via hydrogels increased the equilibrium swelling ratio, elastic modulus and tensile strength. In addition, β-CD increased the hydrophilicity of the hydrogels, resulting in a lower water contact angle and higher cellular adhesion to the hydrogels. In summary, pHEMA/MMA/β-CD hydrogels show great potential as IOL biomaterials that are capable of maintaining the sustained release of anti-inflammatory drugs after cataract surgery. [ABSTRACT FROM AUTHOR]

Abstract: Combination chemotherapy has been a primary management for cancer. Thus a drug delivery system which can administer several drugs simultaneously and control the drug release at the cancer site is desired. Here we synthesized hyperbranched poly(amine-ester) (HPAE) macromers with different degrees of terminal Cation to make injectable hydrogels as a multi-drug delivery system. The aqueous solutions of the macromers were fast transformed into hydrogel at body temperature with a low concentration (0.05 wt%) of ammonium persulfate (APS) but no activator for accelerating the polymerization, since the HPAE macromer with tertiary amines and APS themselves formed a redox system as initiator. Three different types of drugs, doxorubicin hydrochloride (Dox), 5-fluorouracil (5FU) and leucovorin calcium (LC), were used as model drugs in this experiment. This system allows locally releasing single and/or combinations of anticancer drugs simultaneously by a controllable way. Behaviors of drug release can be controlled by the drug-loading methods or/and the Cation degree of macromers loaded with the drug molecules. The drug release period could be prolonged when the drug was loaded into the macromers with high content of CAE macromers exhibited good biocompatibility which was evaluated in L929 and MCF7 cell lines using MTT cell proliferation assay. The swelling behavior and degradation of HPAE hydrogels in vitro were also examined. These results suggest that the HPAE hydrogels hold great potential for use as injectable systems for locally delivering single and/or multiple drugs in chemotherapy of cancer. [Copyright &y& Elsevier]

Abstract: The drawbacks of poloxamer hydrogel, such as dissolving quickly in aqueous solution, have limited its biomedical application. In order to improve the stability of hydrogel, a novel system was developed by combining the reversible thermo-sensitive property of poloxamer 407 and the thiol-ene reactivity between the acrylate and thiol groups. It was found that the sol–gel transition of the acrylate/thiol modified poloxamer 407 mixture could be achieved at body temperature even with a low concentration of 17.5 wt.%. Meanwhile, the reaction between the acrylate and thiol modified poloxamer 407s occurred spontaneously in mimic physiological conditions, thus the hydrogel with crosslinking structure was formed. As a result, the stability of the crosslinked hydrogel was enhanced remarkably, and the release time of the drug from the crosslinked hydrogel was about 4.0 times as long as that from the poloxamer 407 hydrogel. In vitro and in vivo experiments revealed that the biocompatibilities of the modified poloxamer 407 hydrogel were similar to that of poloxamer 407. These results indicate that the modified poloxamer 407s have potential applications in controlled drug release, tissue engineering and cell encapsulation etc. [Copyright &y& Elsevier]