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Purpose We created and evaluated an enhanced topical delivery system featuring a combination of highly skin-permeable growth factors (GFs), quercetin (QCN), and oxygen; these synergistically accelerated re-epithelialization and granulation tissue formation of/in diabetic wounds by increasing the levels of GFs and antioxidants, and the oxygen partial pressure, at the wound site. Methods To enhance the therapeutic effects of exogenous administration of GFs for the treatment of diabetic wounds, we prepared highly skin-permeable GF complexes comprised of epidermal growth factor (EGF), insulin-like growth factor-I (IGF-I), platelet-derived growth factor-A (PDGF-A), and basic fibroblast growth factor (bFGF), genetically attached, via the N-termini, to a low-molecular-weight protamine (LMWP) to form LMWP-EGF, LMWP-IGF-I, LMWP-PDGF-A, and LMWP-bFGF, respectively. Furthermore, quercetin (QCN)- and oxygen-carrying 1-bromoperfluorooctane (PFOB)-loaded nanoemulsions (QCN-NE and OXY-PFOB-NE) were developed to improve the topical delivery of QCN and oxygen, respectively. After confirming the enhanced penetration of LMWP-GFs, QCN-NE, and oxygen delivered from OXY-PFOB-NE across human epidermis, we evaluated the effects of combining LMWP-GFs, QCN-NE, and OXY-PFOB-NE on proliferation of keratinocytes and fibroblasts, and the chronic wound closure rate of a diabetic mouse model. Results The optimal ratios of LMWP-EGF, LMWP-IGF-I, LMWP-PDGF-A, LMWP-bFGF, QCN-NE, and OXY-PFOB-NE were 1, 1, 0.02, 0.02, 0.2, and 60, respectively. Moreover, a Carbopol hydrogel containing LMWP-GFs, QCN-NE, and OXY-PFOB-NE (LMWP-GFs/QCN-NE/OXY-PFOB-NE-GEL) significantly improved scratch-wound recovery of keratinocytes and fibroblasts in vitro compared to that afforded by hydrogels containing each component alone. LMWP-GFs/QCN-NE/OXY-PFOB-NE-GEL significantly accelerated wound-healing in a diabetic mouse model, decreasing wound size by 54 and 35% compared to the vehicle and LMWP-GFs, respectively. Conclusion LMWP-GFs/QCN-NE/OXY-PFOB-NE-GEL synergistically accelerated the healing of chronic wounds, exerting both rapid and prolonged effects.

In this study, we report a new multifunctional nanoparticle with antioxidative and antibacterial activities in vitro. ZnO@GA nanoparticles were fabricated by coordinated covalent bonding of the antioxidant gallic acid (GA) on the surface of ZnO nanoparticles. This addition imparts both antioxidant activity and high affinity for the bacterial cell membrane. Antioxidative activities at various concentrations were evaluated using a 2,2′-azino-bis(ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging method. Antibacterial activities were evaluated against Gram-positive bacteria (Staphylococcus aureus: S. aureus), including several strains of methicillin-resistant S. aureus (MRSA), and Gram-negative bacteria (Escherichia coli). The functionalized ZnO@GA nanoparticles showed good antioxidative activity (69.71%), and the bactericidal activity of these nanoparticles was also increased compared to that of non-functionalized ZnO nanoparticles, with particularly effective inhibition and high selectivity for MRSA strains. The results indicate that multifunctional ZnO nanoparticles conjugated to GA molecules via a simple surface modification process displaying both antioxidant and antibacterial activity, suggesting a possibility to use it as an antibacterial agent for removing MRSA.

Sibutramine [1-(4-chlorophynyl)-N,N-dimethyl-a-(2-methylpropyl)cyclobutane methane amine] is a newer antiobesity drug with a novel mechanism of action.1) It contains a potent inhibitor of the reuptake of noradrenaline (NA), serotonin (5-HT) and may stimulate thermogenesis by its activation of b 3 -adrenoceptors in brown adipose tissue. [2][3][4] In human subjects, sibutramine is rapidly metabolized to an Nmono-desmethyl metabolite (desmethylsibutramine [Metabolite I]) and an N,N-didesmethyl metabolite (didesmethylsibutramine [Metabolite II]). The in vivo effects of sibutramine are predominantly the results of the action of the above 2 metabolites. 4-7)Sibutramine hydrochloride monohydrate is the commercially available formulation of sibutramine with the relatively high solubility of 2.9 mg/ml at pH 5.2 and melting point of 190°C. 4,8) However, sibutramine base with low solubility has not been used in commercial formulation. Various oral formulations of sibutramine such as another salt form such as sibutramine mesylate 9,10) and sibutramine tartrate, 11) solid dispersions with poloxamer [12][13][14] and inclusion complex. 15)One of the well established method for increasing the solubility and bioavailability of poorly water-soluble drugs is solid dispersion.16) Several conventional methods such as melting, solvent evaporation and solvent wetting were reported to prepare solid dispersions. 17,18) However, the solid dispersion prepared by melting method with high temperature might chemically decompose the drugs. 19,20) In the case of solvent evaporation and solvent wetting method, the drug in the solid dispersions changed to amorphous form, resulting that the drug might be unstable. 18) Furthermore, a large amount of hydrophilic carriers against drug in these conventional solid dispersions must be needed to improve the solubility of poorly water-soluble drugs. 21,22) In this study, to improve the bioavailability of poorly water-soluble sibutramine base, various sibutramine baseloaded solid dispersions were prepared with water, hydroxypropylmethyl cellulose (HPMC), poloxamer and citric acid using spray-drying technique. The effect of HPMC, poloxamer and citric acid on the aqueous solubility of sibutramine was then investigated. The physicochemical properties of solid dispersion were investigated using scanning electron microscope (SEM), differential scanning calorimetry (DSC) and X-ray powder diffraction. The dissolution and pharmacokinetics in rats of solid dispersion were evaluated compared to the sibutramine hydrochloride monohydrate-loaded commercial product (Reductil ® ). This commercial product is a conventional capsule which contains 100 mg sibutramine hydrochloride monohydrate and is usually taken multiple times a day. Poloxamer has been employed to enhance the solubility and bioavailability of poorly water-soluble drugs. 19,23) HPMC is frequently used in the preparation of conventional pharmaceutical oral dosage form due to its hydrophilic and soft property. 24,25) To develop a novel sibutramine base-...