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Ureteral stents are widely used in the department of urology, while the stent could result in many stent-associated complications, such as encrustation, a forgotten stent and patient discomfort. Thus, we developed a novel gradient degradable ureteral stent, which could degrade gradient in vivo, and assessed its effectiveness of the drainage, degradation and biocompatibility in a beagle dog model. In the present study, the degradation time and cytotoxicity were investigated in vitro. And the beagle dogs were inserted with a degradable stent or a biostable stent, and blood studies, liver function tests, renal function tests, urine studies, X-ray, excretory urograms and computerized tomography were performed at immediately, two weeks, four weeks and six weeks postoperative. The results showed that the drainage of the novel stent is similar to the conventional stent, while the biocompatibility and antibacterial ability of the novel stents are better than the conventional stents. The stents we developed provide an alternative for urologists and more assays would be performed in detail to assess the property of the stents.

In the present study, polyurethane materials were obtained from castor oil, polycaprolactone and isophorone diisocyanate by incorporating different concentrations of chitosan (0.5, 1.0 and 2.0% w/w) as an additive to improve the mechanical properties and the biological activity of polyurethanes. The polyurethanes were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, stress/strain fracture tests and swelling analysis, and the hydrophilic character of the surface was determined by contact angle trials. The objectives of the study were to evaluate the effect of the incorporation of chitosan on the changes of the physico-chemical and mechanical properties and the in vitro biological activity of the polyurethanes. It was found that the incorporation of chitosan enhances the ultimate tensile strength of the polyurethanes and does not affect the strain at fracture in polyurethanes with 5% w/w of polycaprolactone and concentrations of chitosan ranging from 0 to 2% w/w. In addition, PCL5-Q-PU formulations and their degradation products did not affect cell viability of L929 mouse fibroblast and 3T3, respectively. Polyurethane formulations showed antibacterial activities against Staphylococcus aureus and Escherichia coli bacteria. The results of this study have highlighted the potential biomedical application of this polyurethanes related to soft and cardiovascular tissues., (© The Author(s) 2016.)

Technological advancement has assisted in developing various availabilities of wound products that help in not only in healing and preventing infection but also in providing patients' comfort and pain reduction during application. However, most of advanced wound healing products in Thailand were imported at high costs to patients. Nowadays, there are increased numbers of local researches of herbs that could provide healing environment for successful wound care. Herbal wound products are currently being introduced as alternatives to those imported dressings. The aim of this study was to report the clinical efficacy of using polyester containing herbal extract dressings in healing of second-degree burns. The volunteers were divided by simply randomized method into the study group of patient using polyester containing herbal extract dressing and the control group of patients treating with dressings that are commercially available and common use. The standard treatment protocols were performed at every 3 days of dressing change. Comparative evaluation consisted of time of healing, length of hospital stays, pain analog score assessment, percentage of infection, and descriptive notification of unfavorable clinical symptoms or signs or side effects., (© The Author(s) 2016.)

Background: In recent years the use of biodegradable suture anchors for treating tendon and ligament pathology in hand surgery became popular. These materials are biocompatible, radiolucent, and load sharing, as they incrementally transfer load to surrounding bone during the resorption process. Despite these numerous advantages, polyglycolic (PGA) and poly-L-lactic acid (PLLA) have become a problem because of the potential risk for foreign body reactions. Methods: This article presents a case of an intraosseous foreign body reaction and massive osteolysis of the proximal carpal after dorsal lunate dislocation repair with bioabsorbable suture anchors. Results: Because of the persistent pain and the decreased strength, a proximal row carpectomy was performed 12-months after the initial trauma. Conclusions: Hand surgeons should be aware of the possibility of a late foreign body reaction, that could be especially severe in carpal bones., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Patients undergoing endovascular aneurysm repair (EVAR) due to abdominal aortic aneurysm often develop an inflammatory response, postimplantation syndrome (PIS) where fever and leukocytosis are common. Previous studies suggest that type of stent graft material (polyester or polytetrafluoroethylene [PTFE]) plays a role., Objectives: To investigate the effect of stent graft material on the inflammatory response and length of hospital stay in patients undergoing standard elective EVAR., Methods: Sixty-nine elective EVAR patients were included in this observational study. To avoid comparing patients with a different graft location and stent graft burden, 12 cases were excluded as well as cases with complication or simultaneous open surgical procedures, leaving 45 patients (32 with polyester and 13 with PTFE graft) for final analysis. Tympanic temperature, C-reactive protein (CRP), white blood cell (WBC), and procalcitonin (PCT) were measured on days -1 and +1 and +3. Duration of in-hospital stay and frequency of PIS were recorded., Results: The PIS was diagnosed in 9 (28.1%) of the 32 polyester cases and in 1 (7.7%) of the 13 cases in the PTFE group (P = .24). Median (interquartile range) in-hospital stay was 5 (5-6) days in the polyester group and 4 (4-5) days in the PTFE group (P = .009). On day +3, in the polyester group, mean CRP was 154 (95% confidence interval: 127-182) mg/L, WBC 9.5 (8.4-10.5) ×10(9)/L, and PCT 0.17 (0.12-0.21) ng/mL. In the PTFE group, mean CRP was 70 (32-109) mg/L (P = .001), WBC 8.8 (6.4-11.1) ×10(9)/L (P = .37), and PCT 0.09 (0.06-0.13) ng/mL (P = .009) on day +3., Conclusion: Standard EVAR with polyester stent grafts appears to result in a trend toward a more pronounced inflammatory reaction than similar EVAR using PTFE and is associated with a longer in-hospital stay., (© The Author(s) 2015.)

The process of molecular self-assembly plays a crucial role in formulation of polymeric nanoparticulated drug delivery carriers as it creates the possibility for enhanced drug encapsulation and carrier surface engineering. This study aimed to develop a novel self-assembled polymeric micelles for targeted delivery in tumor cells in order to overcome not only various drawbacks of 7-ethyl-10-hydroxy camptothecin (SN-38) but also various reported limitations of other drug delivery systems, especially low drug loading and premature release. Custom synthesized amphiphilic triblock copolymer poly(acrylic acid)-poly(ɛ-caprolactone)-poly(acrylic acid) (PAA(13)-PCL(35)-PAA(13)) was used to prepare kinetically stable micelles by nanoprecipitation and modified nanoprecipitation procedure. Core-shell micelles with diameter of 120-140 nm, negative zeta potential and satisfactory drug loading were produced. The prepared formulations were stable in pH range of 3-12 and in media with NaCl concentration <1 mol/l. Screening mixed level factorial 3 × 2(2) design identified that the process temperature as well as the type of organic solvent has influence upon the efficacy of encapsulation, particle size, dissolution rate and burst release. Fourier transform infrared and differential scanning calorimetry analyses confirmed the entrapment of the active substance into the micelles. The kinetic analysis of dissolution studies revealed that the main mechanism of drug release from the prepared formulations is Fickian diffusion. Growth inhibition studies as well as DNA fragmentation assay performed on SW-480 cell lines clearly demonstrated increased growth inhibition effect and presence of fragmented DNA in cells treated with loaded micelles compared to SN-38 solution. Altogether, these results point out to potential biomedical and clinical application of PAA-PCL-PAA systems in the future., (© The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Background: Replacement of the meniscus by an implant could potentially avoid cartilage degeneration., Hypothesis: An implant of degradable polycaprolacton-polyurethane should act as a temporary scaffold enabling regeneration of a new meniscus by slow degradation of the polymer and simultaneous in-growth and differentiation of tissues into the typical cartilage-like tissue of the meniscus., Study Design: Controlled laboratory study., Methods: In 13 dogs' knees, the lateral meniscus was replaced with a porous polymer implant (6 and 7 for 6- and 24-month follow-up, respectively); in 7 knees only a meniscectomy was performed. In 6 knees, no surgery was performed. After 6 and 24 months, the implants and the articular cartilage were histologically evaluated. Compression-stress tests were performed on implant biopsy specimens., Results: The implants were fully integrated into the tissue without formation of a capsule. The foreign body reaction did not exceed grade I. Differentiation from fibrous- to cartilage-like tissue was pronounced after 24 months. Viable cells were particularly absent after 24 months in central parts of the most anterior part of the scaffold. The mechanical properties of the implants were intermediate between the scaffold before implantation and native meniscus tissue and were not different between 6 and 24 months. After both 6 and 24 months, small areas of the implant were not covered with tissue. Cartilage degeneration was not prevented., Conclusion: A final remodeling of tissue into neomeniscus tissue could not take place since the original structure of the polymer was still present after 24 months. The implant did not prevent cartilage degradation. Several factors are discussed that may be responsible for this., Clinical Relevance: Although clinical application of a polymer implant for the replacement of the entire meniscus is not supported by this study, the authors strongly believe in the concept, but further improvements in the implant and surgical technique are needed before such an implant can be recommended for human clinical use.

Porous PEGT/PBT implants with different physico-chemical characteristics were evaluated to identify its potential as biodegradable and biofunctional soft tissue filler. Implants (50 x 10 x 5 mm3) were implanted subcutaneously in mini-pigs and tissue response, tissue volume generated and its consistency were assessed quantitatively with a 52 weeks follow-up. The absence of wound edema, skin irritation, and chronic inflammation demonstrated biocompatibility of all implants evaluated. The hydrophobic implants induced the mildest foreign body response, generated highest amount of connective tissue and demonstrated a decrease in copolymer MW of 34-37% compared to 90% decrease of the hydrophilic implants. The rate and extent of copolymer fragmentation seems to be the determining factor of success of soft tissue augmentation using porous PEGT/PBT copolymer implants.

The purpose of this study was to evaluate the healing at 6 months of aortic stent-grafts custom-made by using Z stents and woven polyester in an animal model. Stent-grafts were built by a published method using autoexpandable stainless steel stents continuously compiled with polyester sutures and covered with a woven polyester membrane. Fourteen stent-grafts of 3 different designs were deployed under fluoroscopic control into the thoracic and the abdominal aorta of 7 adult sheep. At 6 months, all the implants of the sheep that survived the implantation were angiographed and harvested for macroscopy and microscopy. All stent-grafts were implanted successfully and remained patent from then to the explantation procedure. All stent-grafts implanted among the 6 of 7 (86%) animals that survived after the implantation remained patent, stayed free from local complications, and did not migrate during more than 6 months. In all these cases during this period, the implant functioned as a satisfactory aortic substitute while the aortic segment containing the graft kept a normal structure. There was no adverse effects of the presence of the implant upon the aorta or the animal. Stent-grafts home-made according to the described methods gave results at 6 months in this animal model compatible with a safe clinical application among humans.

A 63-year-old woman complained of acute swelling and pain in her ankle at 15 months, after fixation of a talar neck fracture with poly-L-lactide rods. Roentgenographic and laboratory data revealed no abnormalities, but T1-weighted magnetic resonance imaging showed a diffuse area of low intensity in the talus. After nonweightbearing for 1 month, local findings had disappeared and the area of low intensity shown by magnetic resonance imaging had decreased without surgical treatment. Although there have been some reports of aseptic swelling or synovitis after fixation of a fracture with polyglycolide rods or screws, there has been no report of such cases with poly-L-lactide rods or screws.