A novel medical adhesive was prepared by blending poly(lactic acid) (PLA) with poly(trimethylene carbonate) (PTMC) in ethyl acetate, and the two materials were proven to be biodegradable and biocompatible. The medical adhesive was characterized by ¹H nuclear magnetic resonance (¹HNMR), gel permeation chromatography (GPC), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The water vapor transmission rate (WVTR) of this material was measured to be 7.13 g·cm⁻²·24 h⁻¹. Its degree of comfortability was confirmed by the extensibility (E) and the permanent set (PS), which were approximately 7.83 N·cm⁻² and 18.83%, respectively. In vivo tests regarding rabbit immunoglobulin M (IgM), rabbit immunoglobulin G (IgG), rabbit bone alkaline phosphatase (BALP), rabbit interleukin 6 (IL-6), rabbit interleukin 10 (IL-10), rabbit tumor necrosis factor α(TNFα), glutamic-oxaloacetic transaminase (AST/GOT), glutamic-pyruvic transaminase (ALT/GPT), alkaline phosphatase (AKP), blood urea nitrogen (BUN) and creatinine (Cr) indicated that the PLA-PTMC medical adhesive was not harmful to the liver and kidneys. Finally, pathological sections indicated that PLA-PTMC was more effective than the control group. These data suggest that in addition to having a positive effect on hemostasis and no sensibility to wounds, PLA-PTMC can efficiently prevent infections and has great potential as a medical adhesive.

BF-30 is a single chain polypeptide of an N-segment with an α-helix from cathelicidin gene encoding, and it contains 30 amino acid residues, with a relative molecular mass and isoelectric point of 3637.54 and 11.79, respectively. Cathelicidin-BF-30 was entrapped in four-arm star-shaped poly(ethylene glycol-b-dl-lactic acid-co-glycolic acid) block copolymers (4-arm-PEG-PLGA) by a double-emulsion solvent-evaporation method. Three release phases of cathelicidin-BF-30loaded 4-arm-PEG-PLGA microspheres were observed, including an initial burst-release phase, followed by a lag phase with minimal drug release and finally a secondary zero-order release phase. The delivery system released BF-30 over more than 15 days in vitro. Furthermore, the material for preparing the microspheres has good biocompatibility and biodegradability. Additionally, based on the drug resistance of food pathogenic bacteria, the antibacterial effects of BF-30 on Shigella dysenteriae CMCC 51105 (Sh. dysenteriae CMCC 51105), Salmonella typhi (S. typhi) and Staphylococcus aureus (S. aureus) as well as the stability of the in vitro release of the BF-30-loded microspheres were studied. The α-helix secondary structure and antibacterial activity of released BF-30 were retained and compared with native peptide. These BF-30 loaded microspheres presented <10% hemolysis and no toxicity for HEK293T cells even at the highest tested concentration (150 μg/mL), indicating that they are hemocompatible and a promising delivery and protection system for BF-30 peptide.

In this paper, Environmental Sciences, the reform of teaching methods, correspondence, through the status and characteristics of environmental science education by correspondence analysis. With the author several years to engage in adult correspondence education in reality. Of environmental science and education by correspondence teaching mode, teaching methods, teaching contents, teaching methods, teaching methods, the reform put forward some ideas and proposals. Introduction 1 Environmental Science correspondence students there is age gap, knowledge level uneven, different occupation, learning motivation of different characteristics and rules, therefore, teaching is difficult. We cannot copy the teaching mode in teaching full-time[1] , should have a suitable teaching methods in correspondence education. Course of environmental science related, content, and piecemeal, hard hard to remember, experiments, and concrete, not empty, if often method, in accordance with the requirements of the syllabus content, tend to echo what the books say, make content boring, teaching effect is poor, can not adapt to the characteristics and requirements of correspondence teaching. Therefore, the need for traditional teaching mode reform. The problem of the reform of scientific teaching methods, through the analysis of the environmental science correspondence education present situation and characteristics. The author is engaged in the adult correspondence education in recent years, put forward some ideas and suggestions on the reform of environmental science education by correspondence teaching mode, teaching form, teaching content, teaching means, teaching method, attempts to provide a little help for correspondence environmental science teaching, for outstanding students of environmental science professional correspondence provides a guidance. The change of teaching mode, select the appropriate form of teaching, pay attention to the correct guidance, grasp self-study. Correspondence education is the "self-study, face-to-face while" teaching mode. The main way to acquire knowledge of students is self-taught, learning guidance is an important link in the correspondence teaching, we should do a good job. The class teaching hours in total have 2/3 time self-study and correspondence students counseling time, but most bear family, work, learn the three heavy pressure, although it has a strong desire for knowledge and learning ability, but often can not guarantee the time and attention, so that to guarantee the teaching quality, we must change the