Rectifying disorder of extracellular matrix to suppress urethral stricture by protein nanofilm-controlled drug delivery from urinary catheter

Urethral stricture secondary to urethral injury, afflicting both patients and urologists, is initiated by excessive deposition of extracellular matrix in the submucosal and periurethral tissues. Although various anti-fibrotic drugs have been applied to urethral stricture by irrigation or submucosal injection, their clinical feasibility and effectiveness are limited. Here, to target the pathological state of the extracellular matrix, we design a protein-based nanofilm-controlled drug delivery system and assemble it on the catheter. This approach, which integrates excellent anti-biofilm properties with stable and controlled drug delivery for tens of days in one step, ensures optimal efficacy and negligible side effects while preventing biofilm-related infections. In a rabbit model of urethral injury, the anti-fibrotic catheter maintains extracellular matrix homeostasis by reducing fibroblast-derived collagen production and enhancing metalloproteinase 1-induced collagen degradation, resulting in a greater improvement in lumen stenosis than other topical therapies for urethral stricture prevention. Such facilely fabricated biocompatible coating with antibacterial contamination and sustained-drug-release functionality could not only benefit populations at high risk of urethral stricture but also serve as an advanced paradigm for a range of biomedical applications.

Endovascular Metal Devices for the Treatment of Cerebrovascular Diseases

Cerebrovascular disease involves various medical disorders that obstruct brain blood vessels or deteriorate cerebral circulation, resulting in ischemic or hemorrhagic stroke. Nowadays, platinum coils with or without biological modification have become routine embolization devices to reduce the risk of cerebral aneurysm bleeding. Additionally, many intracranial stents, flow diverters, and stent retrievers have been invented with uniquely designed structures. To accelerate the translation of these devices into clinical usage, an in-depth understanding of the mechanical and material performance of these metal-based devices is critical. However, considering the more distal location and tortuous anatomic characteristics of cerebral arteries, present devices still risk failing to arrive at target lesions. Consequently, more flexible endovascular devices and novel designs are under urgent demand to overcome the deficiencies of existing devices. Herein, the pros and cons of the current structural designs are discussed when these devices are applied to the treatment of diseases ranging broadly from hemorrhages to ischemic strokes, in order to encourage further development of such kind of devices and investigation of their use in the clinic. Moreover, novel biodegradable materials and drug elution techniques, and the design, safety, and efficacy of personalized devices for further clinical applications in cerebral vasculature are discussed.

Biodegradable polymer drug-eluting stents versus first-generation durable polymer drug-eluting stents: A systematic review and meta-analysis of 12 randomized controlled trials

BACKGROUND

Even if drug-eluting stents (DES) showed beneficial effects in patients with coronary artery diseases (CADs), limitations have been observed with the first-generation durable polymer DES (DP-DES). Recently, biodegradable polymer DES (BP-DES) have been approved to be used as an alternative to DP-DES, with potential benefits. We aimed to systematically compare BP-DES with the first-generation DP-DES using a large number of randomized patients.

METHODS

Electronic databases were searched for randomized controlled trials (RCTs) comparing BP-DES with first-generation DP-DES. The main endpoints were the long-term (≥2 years) adverse clinical outcomes that were reported with these 2 types of DES. We calculated odds ratios (ORs) with 95% confidence intervals (CIs) and the analysis was carried out by RevMan 5.3 software.

RESULTS

Twelve trials with a total number of 13,480 patients (7730 and 5750 patients were treated by BP-DES and first-generation DP-DES, respectively) were included. During a long-term follow-up period of ≥2 years, mortality, myocardial infarction (MI), target lesion revascularization (TLR), and major adverse cardiac events (MACEs) were not significantly different between these 2 groups with OR: 0.84, 95% CI: 0.66-1.07; P = .16, I = 0%, OR: 1.01, 95% CI: 0.45-2.27; P = .98, I = 0%, OR: 0.91, 95% CI: 0.75-1.11; P = .37, I = 0% and OR: 0.86, 95% CI: 0.44-1.67; P = .65, I = 0%, respectively. Long-term total stent thrombosis (ST), definite ST, and probable ST were also not significantly different between BP-DES and the first-generation DP-DES with OR: 0.77, 95% CI: 0.50-1.18; P = .22, I = 0%, OR: 0.71, 95% CI: 0.43-1.18; P = .19, I = 0% and OR: 1.31, 95% CI: 0.56-3.08; P = .53, I = 6%, respectively.

CONCLUSION

Long-term mortality, MI, TLR, MACEs, and ST were not significantly different between BP-DES and the first-generation DP-DES. However, the follow-up period was restricted to only 3 years in this analysis.

Controlled Slow-Release Drug-Eluting Stents for the Prevention of Coronary Restenosis: Recent Progress and Future Prospects

Drug-eluting stents (DES) have become more widely used by cardiologists than bare metal stents (BMS) because of their better ability to control restenosis. However, recognized negative events, particularly including delayed or incomplete endothelialization and late stent thrombosis, have caused concerns over the long-term safety of DES. Although stent-based drug delivery can facilitate a drug's release directly to the restenosis site, a burst of drug release can seriously affect the pharmacological action and is a major factor accounting for adverse effects. Therefore, the drug release rate has become an important criterion in evaluating DES. The factors affecting the drug release rate include the drug carrier, drug, coating methods, drug storage, elution direction, coating thickness, pore size in the coating, release conditions (release medium, pH value, temperature), and hemodynamics after the stent implantation. A better understanding of how these factors influence drug release is particularly important for the reasonable use of efficient control strategies for drug release. This review summarizes the factors influencing the drug release from DES and presents strategies for enhancing the control of the drug's release, including the stent design, the application of absorbable stents, the development of new polymers, and the application of nanocarriers and improvements in the coating technology. Therefore, this paper provides a reference for the preparation of novel controlled slow-release DES.

Comparison of the safety and efficacy of biodegradable polymer drug-eluting stents versus durable polymer drug-eluting stents: a meta-analysis

Background

A meta-analysis was conducted to assess the safety and efficacy of biodegradable polymer drug-eluting stents (BP-DESs).

Methods

PubMed, Science Direct, China National Knowledge Infrastructure, and Chongqing VIP databases were searched for randomized controlled trials comparing the safety and efficacy of BP-DESs versus durable polymer drug-eluting stents (DP-DESs). Efficacy included the prevalence of target lesion revascularization (TLR), target vessel revascularization (TVR), and late lumen loss (LLL), and safety of these stents at the end of follow-up for the selected research studies were compared.

Results

A total of 16 qualified original studies that addressed a total of 22,211 patients were included in this meta-analysis. In regard to efficacy, no statistically significant difference in TLR (odds ratio (OR) = 0.94, P = 0.30) or TVR (OR 1.01, P = 0.86) was observed between patients treated with BP-DESs and those with DP-DESs. However, there were significant differences in in-stent LLL (weighted mean difference [WMD] = −0.07, P = 0.005) and in-segment LLL (WMD = −0.03, P = 0.05) between patients treated with BP-DESs and with DP-DESs. In terms of safety, there was no significant difference in overall mortality (OR 0.97, P = 0.67), cardiac death (OR 0.99, P = 0.90), early stent thrombosis (ST) and late ST (OR 0.94, P = 0.76; OR 0.96, P = 0.73), or myocardial infarction (MI) (OR 0.99, P = 0.88) between patients treated with BP-DESs and with DP-DESs. However, there was a statistically significant difference in very late ST (OR 0.69, P = 0.007) between these two groups. In addition, the general trend of the rates of TVR and TLR of BP-DESs groups was lower than DP-DESs groups after a 1-year follow-up.

Conclusion

BP-DESs are safe, efficient, and exhibit superior performance to DP-DESs with respect to reducing the occurrence of very late ST and LLL. The general trend of the rates of TVR and TLR of BP-DESs groups was lower than DP-DESs groups after a 1-year follow-up.

Stent Thrombosis with Biodegradable Polymer Drug-Eluting Stents versus Durable Polymer Sirolimus-Eluting Stents: An Update Meta-Analysis

Objective: Durable polymer sirolimus-eluting stents (DP-SES) are associated with a low risk of stent thrombosis; biodegradable polymer drug-eluting stents (BP-DES) were designed to reduce these risks. However, their benefits are still variable. Method: We undertook a meta-analysis of randomized trials identified by systematic searches of Medline, Embase, and the Cochrane Database. Results: Eleven studies (9,676 patients) with a mean follow-up of 22.6 months were included. Overall, compared with DP-SES, BP-DES significantly lowered the rate of definite or probable stent thrombosis (RR, 0.73; 95% CI, 0.55-0.97; p = 0.03; I2 = 0.0%) due to a decreased risk of very late stent thrombosis (RR, 0.26; 95% CI, 0.11-0.63; p = 0.00; I2 = 0.0%). However, BP-DES were associated with a comparable rate of early and late stent thrombosis. Meanwhile, BP-DES were associated with a broadly equivalent risk of target vessel revascularization (RR, 0.90; 95% CI, 0.78-1.03; p = 0.13; I2 = 0.0%), cardiac death (RR, 0.89; 95% CI, 0.72-1.09; p = 0.24; I2 = 0.0%), myocardial infarction (RR, 1.03; 95% CI, 0.84-1.26; p = 0.79; I2 = 0.0%), and major adverse cardiac events (MACE; RR, 0.91; 95% CI, 0.83-1.0; p = 0.08; I2 = 0.0%). Furthermore, angiographic data showed that in-stent and in-segment late luminal loss were similar between the two groups. Conclusions: Compared with DP-SES, BP-DES were associated with a lower rate of very late stent thrombosis and an equivalent risk of MACE. Larger randomized studies are needed to confirm this finding.

Stent thrombosis in patients with coronary artery disease treated with biodegradable polymer drug-eluting stents: an update meta-analysis

Delayed re-endothelialization may be the pathophysiological cause of stent thrombosis (ST). Biodegradable polymer drug-eluting stents (BP-DES) may reduce the risk of ST. The aim of this study was to evaluate the risk of ST in patients treated with BP-DES. Studies were retrieved from the PubMed, Cochrane Library, and EMBASE online databases. Twelve studies (15,155 patients) with long-term follow-up (≥ 12 months) were included. Compared with durable polymer drug-eluting stents (DP-DES), BP-DES did not significantly decrease the risk of definite and probable ST (RR, 0.89; 95% CI, 0.68 to 1.18; P = 0.425) and definite ST (RR, 0.92; 95% CI, 0.66 to 1.30; P = 0.648). Furthermore, there was no difference in the risk of late ST (RR, 1.17; 95% CI, 0.39 to 3.53; P = 0.780). However, the rate of early ST was slightly higher in the BP-DES group (RR, 1.60; 95% CI, 0.94 to 2.73; P = 0.084) than in the DP-DES group. A significant reduction in very late ST (> 12 months) was evident with the BP-DES group (RR, 0.27; 95% CI, 0.10 to 0.68; P = 0.006). Subgroup analysis showed that there was no difference in the rate of definite and probable ST between the BP-DES and first- or second-generation DES groups.Biodegradable polymer stents were associated with a significantly lower risk of very late ST. However, there was no difference in the risk of definite and probable ST between the two groups.

Clinical outcomes of biodegradable polymer drug-eluting stents for percutaneous coronary intervention: an updated meta-analysis of randomized controlled trials

Biodegradable polymer drug-eluting stents (DES) are innovative concepts in the era of percutaneous coronary intervention. We systematically reviewed the latest randomized evidence on the efficacy and safety of biodegradable polymer DES as compared to durable polymer DES. MEDLINE, Embase, and the Cochrane database were searched in August 2013 for eligible randomized controlled trials (RCTs) comparing biodegradable polymer DES with durable polymer DES. Clinical outcomes of interest were mortality, myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), and stent thrombosis. A total of 20 RCTs randomizing 20 021 participants were included, of whom 11 045 were allocated to biodegradable polymer DES and 8976 to durable polymer DES. Treatment of biodegradable polymer DES was not associated with a significant reduction of any of the clinical outcomes (all-cause mortality, odds ratio [OR]: 0.94, 95% confidence interval [CI]: 0.80 to 1.10, P = 0.42; cardiovascular mortality, OR: 0.97, 95% CI: 0.79 to 1.19, P = 0.74; MI, OR: 1.07, 95% CI: 0.91 to 1.26, P = 0.41; TLR, OR: 0.87, 95% CI: 0.69 to 1.08, P = 0.20; TVR, OR: 1.05, 95% CI: 0.85 to 1.28, P = 0.67; definite/probable stent thrombosis, OR: 0.80, 95% CI: 0.59 to 1.07, P = 0.14). Current randomized data indicate that clinical efficacy and safety profiles of biodegradable polymer DES are comparable to those of durable polymer DES. Findings from large-scale studies with rigorous methodology and long follow-up duration are needed.

A randomised comparison of a novel abluminal groove-filled biodegradable polymer sirolimus-eluting stent with a durable polymer everolimus-eluting stent: clinical and angiographic follow-up of the TARGET I trial

AIMS

The study sought to evaluate the safety and efficacy of FIREHAWK, a novel abluminal groove-filled biodegradable polymer sirolimus-eluting stent (SES) for treating patients with single de novo coronary lesions compared with the durable polymer everolimus-eluting stent (EES) XIENCE V.

METHODS AND RESULTS

A total of 458 patients with single de novo native coronary lesions ≤24 mm in length and a coronary artery ≥2.25 to ≤4.0 mm in diameter were enrolled in the TARGET I study, a prospective, randomised, non-inferiority trial. The primary endpoint was in-stent late lumen loss (LLL) at nine-month follow-up. The secondary endpoint, target lesion failure (TLF), was defined as the composite of cardiac death, target vessel myocardial infarction (TVMI), or ischaemia-driven target lesion revascularisation (iTLR). Patients were centrally randomised to treatment with either biodegradable polymer SES (n=227) or durable polymer EES (n=231). The nine-month in-stent LLL of the biodegradable polymer SES was comparable to the EES group (0.13 ± 0.24 mm vs. 0.13 ± 0.18 mm, p=0.94; difference and 95% confidence interval 0.00 [-0.04, 0.04] mm; p for non-inferiority <0.0001). Cardiac death (0.4% vs. 0.0%), TVMI (1.3% vs. 1.7%), iTLR (0.4% vs. 0.4%) and TLF (2.2% vs. 2.2%) were similar between the biodegradable polymer SES and durable polymer EES groups at 12-month follow-up (all p>0.05). No definite/probable stent thrombosis was observed in both of these groups.

CONCLUSIONS

In the multicentre TARGET I trial, the novel abluminal groove-filled biodegradable polymer SES FIREHAWK was non-inferior to the durable polymer EES XIENCE V with respect to the primary endpoint of in-stent LLL at nine months for treating patients with single de novo coronary lesions. The incidences of clinical endpoints were low in both of the stents at 12-month follow-up. (ClinicalTrials.gov identifier: NCT01196819).