Patterned Drug-Eluting Coatings for Tracheal Stents Based on PLA, PLGA, and PCL for the Granulation Formation Reduction: In Vivo Studies.
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ABSTRACT:
SUBMITTER: Sindeeva OA
PROVIDER: S-EPMC8469052 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundCurrently available silicone and metallic stents for tracheal stenosis are associated with many problems. Granulation proliferation is one of the main complications. The present study aimed to evaluate the efficacy of paclitaxel drug-eluting tracheal stent in reducing granulation tissue formation in a canine model, as well as the pharmacokinetic features and safety profiles of the coated drug.MethodsEight beagles were randomly divided into a control group (bare-metal stent group, n = 4) and an experimental group (paclitaxel-eluting stent group, n = 4). The observation period was 5 months. One beagle in both groups was sacrificed at the end of the 1st and 3rd months, respectively. The last two beagles in both groups were sacrificed at the end of 5th month. The proliferation of granulation tissue and changes in tracheal mucosa were compared between the two groups. Blood routine and liver and kidney function were monitored to evaluate the safety of the paclitaxel-eluting stent. The elution method and high-performance liquid chromatography were used to characterize the rate of in vivo release of paclitaxel from the stent.ResultsCompared with the control group, the proliferation of granulation tissue in the experimental group was significantly reduced. The drug release of paclitaxel-eluting stent was the fastest in the 1st month after implantation (up to 70.9%). Then, the release slowed down gradually. By the 5th month, the release reached up to 98.5%. During the observation period, a high concentration of the drug in the trachea (in the stented and adjacent unstented areas) and lung tissue was not noted, and the blood test showed no side effect.ConclusionsThe paclitaxel-eluting stent could safely reduce the granulation tissue formation after stent implantation in vivo, suggesting that the paclitaxel-eluting tracheal stent might be considered for potential use in humans in the future.
| S-EPMC5126163 | biostudies-literature
Project description:Drug-eluting stents (DES) have been widely used for the treatment of cardiovascular diseases. Nevertheless, chronic inflammation and delayed re-endothelialization still represent challenges for their clinical use. In the present work, we developed novel bilayer coatings for stent applications that could overcome these limitations, exclusively using biodegradable plant-based drugs and polymers. In particular, stainless steel surfaces were coated with rutin-loaded zein (the active layer) and cross-linked alginate (the sacrificial layer) via facile dip and spray coating methods. Various mechanical tests and analysis tools, such as infrared spectroscopy, water contact angle measurements, and scanning electron microscopy were used to characterize the coated surfaces. Degradation and release studies of the films were extensively carried out and compared. The release rate of rutin from the bilayer coating reached 66.1 ± 3.2% within 24 hours of incubation (initial burst period), while the rest of the drug was released over 21 days in a sustained manner. Antioxidant assays confirmed that rutin retained its free radical scavenging ability after being eluted in phosphate buffer at 37 °C. In vitro results with human fibroblasts and endothelial cells suggested that the coating materials and their degradation products are highly biocompatible. In conclusion, our novel drug-eluting coatings, fabricated with natural biodegradable polymers, are promising materials for DES applications, allowing a sustained drug delivery and improving the biocompatibility of cardiovascular implanted devices.
| S-EPMC9036829 | biostudies-literature
Project description:Coronary stenting is routinely utilized to treat symptomatic obstructive coronary artery disease. However, the efficacy of bare metal coronary stents has been historically limited by restenosis, which is primarily due to excessive neointima formation. Drug-eluting stents (DES) are composed of a stainless steel backbone encompassed by a polymer in which a variety of drugs that inhibit smooth muscle cell proliferation and excessive neointima formation are incorporated. DES have significantly reduced the incidence of restenosis but are also associated with a small (approximately 0.5% per year) but significant risk of late stent thrombosis. In that regard, estrogen-eluting stents have also undergone clinical evaluation in reducing restenosis with the additional potential benefit of enhancing reendothelialization of the stent surface to reduce stent thrombosis. Estrogen directly promotes vasodilatation, enhances endothelial healing, and prevents smooth muscle cell migration and proliferation. Due to these mechanisms, estrogen has been postulated to reduce neointimal hyperplasia without delaying endothelial healing. In animal studies, estrogen treatment was effective in decreasing neointimal hyperplasia after both balloon angioplasty and stenting regardless of the method of drug delivery. The first uncontrolled human study using estrogen-coated stents demonstrated acceptable efficacy in reducing late lumen loss. However, subsequent randomized clinical trials did not show superiority of estrogen-eluting stents over bare metal stents or DES. Further studies are required to determine optimal dose and method of estrogen delivery with coronary stenting and whether this approach will be a viable alternative to the current DES armamentarium.
| S-EPMC2719737 | biostudies-other
Project description:BackgroundPolymer-free drug-eluting stents (PF-DES) have been demonstrated comparable to permanent polymer drug-eluting stents (PP-DES) during long-term follow-up. As a critical component of drug-eluting stents, antiproliferative drugs may be a confounding factor for the results. Thus, we sought to compare the outcomes of these stents during long-term follow-up, especially in consideration of different stent platforms with the same drugs.MethodsA systemic search was performed to identify the related randomized controlled trials comparing PF-DES with PP-DES. Primary outcomes included short (≤1 year) and long-term (>1 year) target lesion revascularization (TLR), short-term in-stent late luminal loss (LLL) and diameter stenosis (DS). Subgroup analyses stratified by the different platforms with the same proliferative drugs were conducted in TLR, LLL, and DS. Standardized mean differences (SMDs) and risk ratios (RRs) were estimated using fixed /random effects models RESULTS:: A total of 6927 patients extracted from 12 RCTs were enrolled in the meta-analysis. No differences were observed in clinical outcomes of short-term and long-term overall mortality, myocardial infarction and stent thrombosis and angiographic outcomes of short-term in-stent LLL and DS between PF-DES and PP-DES for patients with coronary artery lesions. Nevertheless, compared with PP-DES coated with the same proliferative drugs, PF-DES had significantly increased risks of in-stent LLL (SMD, 0.49; 95% confidence interval [CI], 0.25-0.72) and DS (SMD, 0.67; 95% CI, 0.27-1.07), and long-term TLR (RR, 1.64; 95% CI 1.13-2.39). There were no significant differences in other outcomes.ConclusionsUnder the condition of using same antiproliferative drugs (paclitaxel or sirolimus) in different stent systems, PF-DES are associated with the increased risk of restenosis compared to PP-DES.
| S-EPMC6485796 | biostudies-literature
Project description:There are limited data about clinical outcomes of biodegradable polymer biolimus-eluting BioMatrix stents (BP-BES) and durable polymer everolimus-eluting Xience stents (DP-EES) in real world practice. We sought to compare the clinical outcomes of BP-BES and DP-EES in real world cohorts of patients undergoing percutaneous coronary intervention. A prospective multicenter registry enrolled 999 patients treated with BP-BES and 1,000 patients treated with DP-EES. The primary outcome was target lesion failure, defined as a composite of cardiac death, target vessel-related myocardial infarction, or target lesion revascularization. Definite or probable stent thrombosis was also compared in total and propensity score-matched cohorts. The median follow-up duration was 24 months, and mean age was 65 years (interquartile range, 56-72 years). Patients receiving BP-BES had a lower prevalence of acute coronary syndrome, prior myocardial infarction, multi-vessel disease, bifurcation lesions, and left anterior descending artery lesions than those receiving DP-EES. After propensity score matching (692 pairs), target lesion failure occurred in 22 patients receiving BP-BES and in 25 patients receiving DP-EES (3.2% versus 3.6%; adjusted hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.53 to 1.60; p = 0.77). The risk of definite or probable stent thrombosis did not differ between the 2 groups (0.4% versus 0.4%; adjusted HR, 1.03; 95% CI, 0.21 to 4.98; p = 0.97). The results were consistent across various subgroups. In the propensity score-matched analysis of real world cohorts, BP-BES showed similar clinical outcomes compared to DP-EES. We need to investigate about whether differences in clinical outcome emerge during long-term follow-up.
| S-EPMC5552220 | biostudies-literature
Project description:A facile method for the preparation of large, microporous, drug-loaded particles is presented. High shear bollus injections of silk with cross-linker and drug colloids into super-cooled hexane were utilized to trigger phase separation of silk droplets, followed by immediate freezing at -60°C. A subsequent -20°C freeze-thaw of the frozen droplets resulted in self-assembly (crystallization) of the silk. The silk particles developed an internal interconnected microporous morphology with 0.1-10 µm in diameter pores. The silk particles ranged in diameter from 100 to 1,300 µm, with particle mean diameter and polydispersity controlled by the starting concentration of the cross-linking agent and silk, the rheology of the reaction mixture, and the injection pressure (80 - 300kPa). Cryogranulation provided a one-step process to produce microporous meso-scale silk particles with encapsulated drugs, such as doxorubicin chloride (DoxR), tobramycin sulfate (TS), kanamycin sulfate (KS) or gentamicin sulfate (GS). Almost 100% drug encapsulation efficiency was achieved in the process, and subsequent release profiles depended on the starting concentration of both the drug, silk, and pH of the elution medium. Kirby-Bauer tests and bioluminescent imaging confirmed the retention of anti-bacterial potency of the antibiotics pre-encapsulated in the cryo-particles, and macroparticles cytocompatibility towards human fibroblast and kidney cells.
| S-EPMC6938394 | biostudies-literature
Project description:BackgroundSecond generation drug-eluting stents were developed to improve the safety and efficacy of first generation stents. So far, limited long term randomized data exist comparing the second generation everolimus-eluting stents (EES) with first generation sirolimus-eluting stents (SES).MethodsA prospective, open-label, randomized, single center trial comparing EES and SES in all-comer patients. The primary endpoint was a composite of cardiac mortality, myocardial infarction and target vessel revascularization. Secondary endpoints included individual components of the composite, along with target lesion revascularization and stent thrombosis.ResultsIn total, 977 patients were randomized, of which 498 patients to EES and 479 to SES. Average age was 65.2 ± 11.2 years and 71.6% of the population was male. Fifty percent of patients were treated for acute coronary syndrome, more often for ST-elevation myocardial infarctions in EES patients (13.7% vs. 9.2% in SES). In contrast, SES patients more often had prior interventions and showed more calcified lesions. Two-year follow-up was available in 98% of patients. The primary endpoint occurred in 10.7% of EES patients compared to 10.6% of SES patients (HR 1.00, 95% CI 0.68-1.48). Additionally, secondary endpoints were similar between groups. The rate of stent thrombosis was low for both stent types.ConclusionIn this all-comer population, there were no differences in endpoints between EES and SES during two-year follow-up. Stent thrombosis rates were low, supporting the safety of drug-eluting stent appliance in clinical practice.Trial registrationTrialRegister.nl NTR3170.
| S-EPMC3670908 | biostudies-literature
Project description:BackgroundSirolimus-eluting stents have recently been shown to reduce the risk of restenosis among patients who undergo percutaneous coronary intervention (PCI). Given that sirolimus-eluting stents cost about 4 times as much as conventional stents, and considering the volume of PCI procedures, the decision to use sirolimus-eluting stents has large economic implications.MethodsWe performed an economic evaluation comparing treatment with sirolimus-eluting and conventional stents in patients undergoing PCI and in subgroups based on age and diabetes mellitus status. The probabilities of transition between clinical states and estimates of resource use and health-related quality of life were derived from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) database. Information on effectiveness was based on a meta-analysis of randomized controlled clinical trials (RCTs) comparing sirolimus-eluting and conventional stents.ResultsCost per quality-adjusted life year (QALY) gained in the baseline analysis was Can58,721 dollars. Sirolimus-eluting stents were more cost-effective in patients with diabetes and in those over 75 years of age, the costs per QALY gained being 44,135 dollars and 40,129 dollars, respectively. The results were sensitive to plausible variations in the cost of stents, the estimate of the effectiveness of sirolimus-eluting stents and the assumption that sirolimus-eluting stents would prevent the need for cardiac catheterizations in the subsequent year when no revascularization procedure was performed to treat restenosis.InterpretationThe use of sirolimus-eluting stents is associated with a cost per QALY that is similar to or higher than that of other accepted medical forms of therapy and is associated with a significant incremental cost. Sirolimus-eluting stents are more economically attractive for patients who are at higher risk of restenosis or at a high risk of death if a second revascularization procedure were to be required.
| S-EPMC545758 | biostudies-literature
Project description:"Cable-tie" type biodegradable stents with drug-eluting nanofiber were developed to treat rabbit denuded arteries in this study. Biodegradable stents were fabricated using poly-L-lactide film following being cut and rolled into a cable-tie type stent. Additionally, drug-eluting biodegradable nanofiber tubes were electrospun from a solution containing poly (lactic-co-glycolic acid), rapamycin, and hexafluoroisopropanol, and then mounted onto the stents. The fabricated rapamycin-eluting cable-tie stents exhibited excellent mechanical properties on evaluation of compression test and collapse pressure, and less than 8% weight loss following being immersed in phosphate-buffered saline for 16 weeks. Furthermore, the biodegradable stents delivered high rapamycin concentrations for over 4 weeks and achieved substantial reductions in intimal hyperplasia associated with elevated heme oxygenase-1 and calponin level on the denuded rabbit arteries during 6 months of follow-up. The drug-eluting cable-tie type stents developed in this study might have high potential impacts for the local drug delivery to treat various vascular diseases.
| S-EPMC5427919 | biostudies-literature
Project description:ObjectiveTo compare the efficacy and safety of biodegradable polymer drug eluting stents with those of bare metal stents and durable polymer drug eluting stents.DesignMixed treatment comparison meta-analysis of 258,544 patient years of follow-up from randomized trials.Data sources and study selectionPubMed, Embase, and Central were searched for randomized trials comparing any of the Food and Drug Administration approved durable polymer drug eluting stents (sirolimus eluting, paclitaxel eluting, cobalt chromium everolimus eluting, platinum chromium everolimus eluting, zotarolimus eluting-Endeavor, and zotarolimus eluting-Resolute) or biodegradable polymer drug eluting stents, with each other or against bare metal stents.OutcomesLong term efficacy (target vessel revascularization, target lesion revascularization) and safety (death, myocardial infarction, stent thrombosis). Landmark analysis at more than one year was evaluated to assess the potential late benefit of biodegradable polymer drug eluting stents.ResultsFrom 126 randomized trials and 258,544 patient years of follow-up, for long term efficacy (target vessel revascularization), biodegradable polymer drug eluting stents were superior to paclitaxel eluting stents (rate ratio 0.66, 95% credibility interval 0.57 to 0.78) and zotarolimus eluting stent-Endeavor (0.69, 0.56 to 0.84) but not to newer generation durable polymer drug eluting stents (for example: 1.03, 0.89 to 1.21 versus cobalt chromium everolimus eluting stents). Similarly, biodegradable polymer drug eluting stents were superior to paclitaxel eluting stents (rate ratio 0.61, 0.37 to 0.89) but inferior to cobalt chromium everolimus eluting stents (2.04, 1.27 to 3.35) for long term safety (definite stent thrombosis). In the landmark analysis after one year, biodegradable polymer drug eluting stents were superior to sirolimus eluting stents for definite stent thrombosis (rate ratio 0.29, 0.10 to 0.82) but were associated with increased mortality compared with cobalt chromium everolimus eluting stents (1.52, 1.02 to 2.22). Overall, among all stent types, the newer generation durable polymer drug eluting stents (zotarolimus eluting stent-Resolute, cobalt chromium everolimus eluting stents, and platinum chromium everolimus eluting stents) were the most efficacious (lowest target vessel revascularization rate) stents, and cobalt chromium everolimus eluting stents were the safest with significant reductions in definite stent thrombosis (rate ratio 0.35, 0.21 to 0.53), myocardial infarction (0.65, 0.55 to 0.75), and death (0.72, 0.58 to 0.90) compared with bare metal stents.ConclusionsBiodegradable polymer drug eluting stents are superior to first generation durable polymer drug eluting stents but not to newer generation durable polymer stents in reducing target vessel revascularization. Newer generation durable polymer stents, and especially cobalt chromium everolimus eluting stents, have the best combination of efficacy and safety. The utility of biodegradable polymer stents in the context of excellent clinical outcomes with newer generation durable polymer stents needs to be proven.
| S-EPMC3898413 | biostudies-literature