Mussel-Inspired Polymer-Based Coating Technology for Antifouling and Antibacterial Properties.

Zwitterionic coatings provide a promising antifouling strategy against biofouling adhesion. Quaternary ammonium cationic polymers can effectively kill bacteria on the surface, owing to their positive charges. This strategy can avoid the release of toxic biocides, which is highly desirable for constructing coatings for biomedical devices. The present work aims to develop a facile method by covalently grafting zwitterionic and cationic copolymers containing aldehydes to the remaining amine groups of self-polymerized dopamine. Reversible addition-fragmentation chain transfer polymerization was used to copolymerize either zwitterionic 2-methacryloyloxyethyl phosphorylcholine monomer (MPC) or cationic 2-(methacryloyloxy)ethyl trimethylammonium monomer (META) with 4-formyl phenyl methacrylate monomer (FPMA), and the formed copolymers poly(MPC-st-FPMA) and poly(META-st-FPMA) are denoted as MPF and MTF, respectively. MPF and MTF copolymers were then covalently grafted onto the amino groups of polydopamine-coated surfaces. PDA/MPF/MTF-coated surfaces exhibited antibacterial and antifouling properties against S. aureus, E. coli, and bovine serum albumin protein. In addition, they showed excellent viability of normal human lung fibroblast cells MRC-5. We expect the facile surface modification strategy discussed here to be applicable to medical device manufacturing.

A Novel Therapy for Laryngotracheal Stenosis: Treatment With Ethosomes Containing 5-Fluorouracil.

PURPOSE: The purpose of our article was to explore the effect of ethosomes containing 5-fluorouracil (5-FU) with different sizes on laryngotracheal stenosis treatment. METHODS: The physical characteristics of ethosomes containing 5-FU were investigated, including size, shape, and entrapment percentage. The effect of ethosomes containing 5-FU was evaluated on the airway stenosis rabbit model. The formation of fibrous/scar tissue was investigated by hematoxylin and eosin (HE) staining, and the permeation depth was observed under fluorescence microscope. RESULTS: The mean sizes of 5-FU ethosomes extruded by D=50 nm and D=100 nm pore were 60±10 nm and 110±13 nm, respectively. The 5-FU entrapment percentage of ethosomes was determined to be 15% (D=60±10 nm) and 32% (D=110±13 nm). After being treated by ethosomes containing 5-FU (D=60±10 nm), the fibroblast and collagenous fiber distributed sparsely in the deep scar tissue. The permeation capability of ethosomes containing 5-FU (D=60 nm) was significantly better than ethosomes (D=110 nm). Besides, the 5-FU ethosomes resulted in less stenosis than 5-FU only. CONCLUSIONS: Topical administration of 5-FU ethosomes may be a novel candidate therapy for laryngotracheal stenosis treatment.

Enhanced in vivo delivery of 5-fluorouracil by ethosomal gels in rabbit ear hypertrophic scar model.

Applying Ethosomal Gels (EGs) in transdermal drug delivery systems has evoked considerable interest because of their good water-solubility and biocompatibility. However, there has not been an explicit description of applying EGs as a vehicle for hypertrophic scars treatment. Here, a novel transdermal EGs loaded with 5-fluorouracil (5-FU EGs) was successfully prepared and characterized. The stability assay in vitro revealed that 5-FU EGs stored for a period of 30 days at 4 ± 1 °C had a better size stability than that at 25 ± 1 °C. Furthermore, using confocal laser scanning microscopy, EGs labeled with Rhodamine 6 G penetrated into the deep dermis of the hypertrophic scar within 24 h in the rabbit ear hypertrophic model suggested that the EGs were an optional delivery carrier through scar tissues. In addition, the value of the Scar Elevation Index (SEI) of 5-FU EGs group in the rabbit ear scar model was lower than that of 5-FU Phosphate Buffered Saline gel and Control groups. To conclude, these results suggest that EGs delivery system loaded 5-fluorouracil is a perfect candidate drug for hypertrophic scars therapy in future.

Preparation of levofloxacin thermo-sensitive gel and clinical application in the treatment of suppurative otitis media.

CONCLUSION: The levofloxacin thermo-sensitive gel prepared using 17% poloxamer 407 (P407) can successfully treat suppurative otitis media (SOM) through the well-controlled release of levofloxacin targeted against the inflammation. OBJECTIVE: To evaluate the preparation method and therapeutic effect of levofloxacin thermo-sensitive gel used in the treatment of SOM. METHODS: The phase inversion temperatures of 16%, 17%, 18%, 19%, and 20% P407 or P407 solution with 3 mg/ml levofloxacin were determined and the one close to 34(°)C was selected as the optimal concentration. Then a model of SOM was induced by injection of 0.1 ml Staphylococcus aureus (1 × 10(8)/L) in the left ear of 32 Sprague Dawley (SD) rats. Normal saline injected in the right ear was used as the control. Then rats were treated with 0.1 ml normal saline (group A), levofloxacin (group B), P407 (group C), and levofloxacin thermo-sensitive gel (group D) (n = 8). The tympanic membranes were evaluated by otoscopy and hematoxylin and eosin (H&E) staining. RESULTS: The optimal concentration of P407 was 17% and the release of levofloxacin in thermo-sensitive gel followed zero-order kinetics. Levofloxacin thermo-sensitive gel and levofloxacin drops could both alleviate the local inflammation in the first 3 days, but levofloxacin drops could not inhibit the recurrence of SOM, while the levofloxacin gel performed continuous drug delivery into inflammation without recurrence.

[Preparation of ethosomes encapsulated with 5-fluorouracil and the effect of local administered 5-FU ethosome on laryngotracheal stenosis of rabbit].

OBJECTIVE: To evaluate the efficacy of Ethosomes encapsulated with 5-FU in treatment of laryngotracheal stenosis in rabbit models. METHOD: The 5-FU ethosome was prepared by the thin film hydration method, and the size distribution and the encapsulation efficiency was investigated. The tracheal mucosa was scraped about 0.5 cm in width with a nylon brush to induce the scar formation in the airway,then animals were divided into three groups: 5-FU ethosome group,5-FU group and saline group. Drugs were injected into scar by paracentesis under endoscope in each group respectively. The severity of stenosis was observed under laryngofiberoscope immediately, 7, 14, 21 days after administration. RESULT: Airway stenosis of 5-FU ethosome group was not significantly different compared with 5-FU group at 7 days after administration, but 5-FU ethosome significantly reduced the airway stenosis at 21 days after administration when compared with 5-FU group and no restenosis was noticed during the observation period. CONCLUSION: Ethosomes encapsulated with 5-FU was effective for laryngotracheal stenosis. It is a potentially new method for ameliorating airway stenosis originated from granulation tissue.