Amino-functionalized poloxamer 407 with both mucoadhesive and thermosensitive properties: preparation, characterization and application in a vaginal drug delivery system

Lack of mucoadhesive properties is the major drawback to poloxamer 407 (F127)-basedhydrogels for mucosal administration. The objective of the present study was to construct a novel mucoadhesive and thermosensitivehydrogel drug delivery system based on an amino-functionalized poloxamer for vaginal administration. First, amino-functionalized poloxamer 407 (F127-NH) was synthesized and characterized with respect to its micellization behavior and interaction with mucin. Then using acetate gossypol (AG) as model drug, AG-loaded F127-NH-basedhydrogels (NFGs) were evaluated with respect to rheology, drug release,vaginal mucosal adhesion,intravaginal retention and local irritation after vaginal administration to healthy female mice. The results show that F127-NHis capable of forming a thermosensitivehydrogel with sustained drug release properties. An interaction between positively charged F127-NHand negatively charged mucin was revealed by changes in the particle size and zeta potential of mucin particles as well as an increase in the complex modulus of NFG caused by mucin.andfluorescence imaging and quantitative analysis of the amount of AG remaining in mouse vaginal lavage all demonstrated greater intravaginal retention of NFG than that of an unmodified F127-basedhydrogel. In conclusion, amino group functionalization confers valuable mucoadhesive properties on poloxamer 407.

Chemical camouflage of like human B antigens on Rhesus monkey red blood cells with methoxy polyethylene glycol / 中国输血杂志

Objective To observe the chemical camouflage effects of methoxy polyethylene glycol(mPEG) on like human B antigens on Rhesus monkey red blood cell(rRBC) and to study the safety of transfusion with mPEG modified monkey RBC(mPEG rRBC).Methods rRBC were modified with 3mg/ml mPEG. The rRBC blood group and the effects of mPEG modification on blood conversion were assayed by absorption and elution methods.The structural and functional changes of mPEG rRBC were also tested.The survival fraction of mPEG modified like B rRBC in like A recipient monkey were examined by flow cytometry.The transfusion effects of mPEG modified rRBC on recipient's blood and urine were also observed.Results mPEG have been covalently bound to the surface of Rhesus monkey RBC (like human B blood group),mPEG could cover rRBC like B antigen.Transfusion of mPEG modified like B rRBC to like A Rhesus monkey had no harmful effects on the recipient.Conclusion The present study suggests that transfusion of mPEG modified RBC could be safety in experimental animals