With the environmental pollution caused by waste plastics becoming increasingly serious, biodegradable polyester has become the focus of public attention. Poly(butylene adipate-co-terephthalate) (PBAT) is a biodegradable polyester formed by the copolymerization of aliphatic and aromatic groups, which has excellent performance of both. The degradation of PBAT under natural conditions requires strict environmental conditions and long degradation cycle. To address these shortcomings, this study explored the application of cutinase in PBAT degradation and the impact of butylene terephthalate (BT) content on the biodegradability of PBAT, so as to improve the degradation rate of PBAT. Five Polyester degrading enzymes from different sources were selected to degrade PBAT to pick out the most efficient enzyme. Subsequently, the degradation rate of PBAT materials with different BT content were determined and compared. The results showed that cutinase ICCG was the best enzyme for PBAT biodegradation, and the higher the BT content, the lower the degradation rate of PBAT. Furthermore, the optimum temperature, buffer type, pH, the ratio of enzyme to substrate (E/S) and substrate concentration in the degradation system were determined to be 75 ℃, Tris HCl, 9.0, 0.4% and 1.0% respectively. These findings may facilitate the application of cutinase in PBAT degradation.
Polyesters/chemistry* ; Adipates

Star-shaped polymer of epoxidized soybean oil (ESO) and lactide is a new material. Its degradation function has an importance to its applications. There are many factors affecting its degradation. This paper is mainly aimed at investigation in which the surface morphology, pH, molecular weight and weight loss rate, branching ESO-lactide star polymers the degree of change were studied. It was found through the experiments that, the changing rates of the branching ESO-lactide star polymers were slower than the degree of PDLLA change compared to the surface morphology, pH, molecular weight and weight loss rate. This has a guiding significance to the further application of ESO-lactide.
Polyesters ; chemistry ; Polymers ; chemistry ; Soybean Oil ; chemistry

Poly (lactic acid) (PLA) is a polymer synthesized from lactic acid with good biocompatibility and biodegradability. At present, PLA manufactured on industrial scale is mainly synthesized from L-lactic acid. The obtained products have good transparency but poor heat resistance. Adding nucleating agents could increase the crystallinity of PLA, to improve heat resistance. We reviewed the progress of research on organic and inorganic nucleating agents that can be used for PLA synthesis.
Chemical Industry ; Lactic Acid ; Polyesters ; chemistry ; Polymers

Polylactic acid is synthesized indirectly by the polymerization method, according to the standard GB/T 16886.18-2011, the evaluation parameters and methods about chemical characterization of polylactic acid have been established. By using rigorous and comprehensive comparative analysis, the chemical equivalency of domestic and imported polylactic acid materials has been proved, along with the "Medical Device Biology Evaluation and Review Guide", paving the way of using domestic polylactic acid in implantable medical devices.
Equipment and Supplies ; Lactic Acid ; Polyesters ; chemistry ; Polymers

Poly lactic acid (PLA) fibers a biodegradable fiber produced from PLA resin by melt spinning, solvent spinning or electrostatic spinning. Based on the excellent safety, comfortability, environmental protection and good mechanical properties, PLA can be widely applied in textile fabric, nonwoven, filler fabric and many downstream health products application, such as sanitary napkins, baby diapers, facial masks, and wipes.
Biotechnology ; Chemical Industry ; Lactic Acid ; Polyesters ; chemistry ; Polymers

In this review, we presented the industrial status of biomanufactured polyhydroxyalkanoates (PHA), including poly (3-hydroxybutyrate) (PHB), poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly (3-hydroxybutyrate-co-4-hydroxybutyrate) (P3/4HB)), and poly (3-hydroxybutyrate-3-hydroxycaproate) (PHBH). A lot of modification studies, aimed at solving problems of poor thermal stability, narrow processing window and other drawbacks of PHA, are discussed. The properties of PHA can be optimized by using proper modification method, in order to expand its applications.
3-Hydroxybutyric Acid ; Biotechnology ; Hydroxybutyrates ; Polyesters ; Polyhydroxyalkanoates ; chemistry

Nowadays, there are more and more researches on characters and applications of polycaprolactone (PCL). This paper reviews the researches of polycaprolactone, including its synthesis, physical and chemical properties, biodegradation, absorption properties, and its applications in clinical use and drug delivery systems. PCL can be from open ring polymerizaion. It is a kind of semi-crystalline polymer, and has good flexibility. The degradation reaction of PCL is hydrolysis. PCL is not cumulated in the body, and can be totally excreted. It can be used as suture, material for fixation of bone fracture, vector of drug, etc. PCL is widely used in medical area because of its safety, low toxicity, biodegradability.
Biodegradation, Environmental ; Drug Carriers ; Polyesters ; chemical synthesis ; chemistry ; metabolism ; Sutures

This study aims to investigate the preparation process and in vitro release behavior of artesunate polylactic acid microspheres, in order to prepare an artesunate polylactic acid (PLA) administration method suitable for hepatic arterial embolization. With PLA as the material and polyvinyl alcohol (PVA) as the emulsifier, O/W emulsion/solvent evaporation method was adopted to prepare artesunate polylactic acid microspheres, and optimize the preparation process. With drug loading capacity, encapsulation efficiency and particle size as indexes, a single factor analysis was made on PLA concentration, PVA concentration, drug loading ratio and stirring velocity. Through an orthogonal experiment, the optimal processing conditions were determined as follows: PLA concentration was 9. 0% , PVA concentration was 0. 9% , drug loading ratio was 1:2 and stirring velocity was 1 000 r x min(-1). According to the verification of the optimal process, microsphere size, drug loading and entrapment rate of artesunate polylactic acid microspheres were (101.7 +/- 0.37) microm, (30.8 +/- 0.84)%, (53.6 +/- 0.62)%, respectively. The results showed that the optimal process was so reasonable and stable that it could lay foundation for further studies.
Artemisinins ; chemistry ; Calibration ; Drug Compounding ; methods ; Lactic Acid ; chemistry ; Microspheres ; Polyesters ; Polymers ; chemistry ; Polyvinyl Alcohol ; chemistry

Chitin short fiber reinforced polycaprolactone composite was prepared by melting blending method. The cytotoxicity and biocompatibility of pure polycaprolactone and of chitin short fiber reinforced polycaprolactone composite were investigated in order to provide useful scientific basis for clinical application. The biocompatibility of pure polycaprolactone and that of chitin short fiber reinforced polycaprolactone composite were evaluated by a series of tests, including cytotoxicity test in vitro, acute systemic toxicity test, hemolysis test, pyrogen test and sensitivity test. The results showed that the cytotoxicity scores of the two materials were grade 0 and the growth and proliferation of the cultured cells were not significantly inhibited by the two materials. There were no potential allergic materials in the composites and the maceration extract showed no hemolytic reaction, no acute systemic toxicity and no pyrogen reaction. We conclude that the composites have fine biocompatibility and are safe for clinical use in the reconstruction treatment for chest wall defect.
Biocompatible Materials ; chemistry ; Bone Substitutes ; chemistry ; Chitin ; chemistry ; Materials Testing ; Polyesters ; chemistry

BACKGROUNDIn-stent restenosis caused by airway granulation poses a challenge due to the high incidence of recurrence after treatment. Weekly applications of anti-proliferative drugs have potential value in delaying the recurrence of airway obstruction. However, it is not practical to subject patients to repeated bronchoscopy and topical drug applications. We fabricated novel pacilitaxel-eluting tracheal stents with sustained and slow pacilitaxel release, which could inhibit the formation of granulation tissue. And we assessed the quality and drug release behaviors of drug-eluting stents (DESs) in vitro.

METHODSStents were dipped vertically into a coating solution prepared by dissolving 0.5 g (2% w/v) of poly lactic acid-coglycolic acid (PLGA) and 0.025 g (0.1% w/v) of pacilitaxel in 25 ml of dichloromethane. DES morphology was examined by scanning electron microscopy (SEM). Pacilitaxel release kinetics from these DESs was investigated in vitro by shaking in PBS buffer followed by high performance liquid chromatography (HPLC).

RESULTSUsing an orthogonal experimental design, we fabricated numerous pacilitaxel/PLGA eluting tracheal stents to assess optimum coating proportions. The optimum coating proportion was 0.1% (w/v) pacilitaxel and 2% (w/v) PLGA, which resulted in total pacilitaxel loading of (16.380 6 ± 0.002 1) mg/stent. By SEM the coating was very smooth and uniform. Pacilitaxel released from DES was at (0.376 3 ± 0.003 8) mg/d, which is a therapeutic level. There was a prolonged, sustained release of pacilitaxel of >40 days.

CONCLUSIONSPaclitaxel-loaded PLGA coating tracheal stents were successfully developed and evaluated. Quality assessments demonstrated favorable surface morphology as well as sustained and effective drug release behavior, which provides an experimental reference for clinical practitioners.

Drug-Eluting Stents ; Glycolates ; chemistry ; Humans ; Lactic Acid ; chemistry ; Paclitaxel ; chemistry ; Polyesters ; Polymers ; chemistry