The dose-dependence biological effect of laser fluence on rabbit fibroblasts derived from urethral scar

In-vitro study on type I collagen synthesis in low-level laser therapy on the early ligament fibroblasts' healing process

BACKGROUND

Low-level Laser Therapy (LLLT) has demonstrated its potential in promoting fiber matrix maturation, collagen synthesis, and fibroblast proliferation, contributing to tissue regeneration. Our study aimed to investigate the impact of LLLT on collagen type I synthesis, cell proliferation, and viability in human ligament fibroblasts derived from the Anterior Cruciate Ligament (ACL).

METHODS

Tissue samples were obtained from individuals undergoing arthroscopic ACL reconstruction surgery. Primary human fibroblasts were isolated, and immunohistochemical assays confirmed their characteristics. LLLT at 850 nm was administered in three groups: Low dose (1.0 J/cm²), High dose (5.0 J/cm²), and Control (0.0 J/cm²). Cell viability was calculated using a membrane integrity assay, proliferation was determined by automated counting, and collagen type I concentration in cell culture was measured using an immunoassay.

RESULTS

Fibroblasts showed decreased viability after low and high doses of LLLT, increased proliferation at the low dose, and increased collagen synthesis at the high dose on day 10 for both sexes after treatment.

CONCLUSION

Our study demonstrated that LLLT may improve the early ligament healing process by increasing cell proliferation at the low dose and enhancing collagen type I synthesis at the high dose in human ligament fibroblasts.

Surgical reintervention requirements following GreenLight PVP: A single-center experience using three different laser device models

Objective

To assess the incidence, risk factors, and timing of specific causes of reoperations following PVP.

Material and Methods

A retrospective analysis of data on men who underwent GreenLight PVP between 2004 and 2019 in a single center and required surgical intervention for bladder neck contracture (BNC), urethral stricture (US), or persistent/recurrent prostate adenoma.

Results

The overall rate of reoperations was 13.8% during a 61-month median follow-up of 377 patients. Reoperations were due to BNC, US, and adenoma in 7.7%, 5.6%, and 4.8% of cases, respectively. The median interval until reoperation for US (11 months) was significantly shorter. None of the risk factors had any relevance to US. In patients who underwent reoperation for BNC, lasing time and energy were significantly lower, and the prostate volume was smaller; however, the multivariate analysis only identified shorter lasing time as a predictor. In patients who had reoperation for persistent/recurrent adenoma, the PSA was increased, while the prostate volume was non-significantly high, and performance by less-experienced surgeons was associated with a higher rate of reoperations (p < 0.05). A longer lasing time predicted an increased risk of reoperation for adenoma in multivariate analysis.

Conclusions

An unselective utilization of PVP may result in a relatively high rate of reoperations. The correlation of BNC with shorter lasing time may imply a higher risk after PVP of smaller prostates. A longer lasing time predicts an increased risk of reoperation due to persistent/recurrent adenoma, which may be related to higher prostate volumes and inefficient PVP by less-experienced surgeons.

Modulating cationicity of chitosan hydrogel to prevent hypertrophic scar formation during wound healing

It is of great clinical significance to design wound dressing materials with combined excellent wound healing properties and superior capability to suppress hypertrophic scar formation. This study aimed to examine if and how the cationicity of chitosan would affect the hypertrophic scar-related outcomes, through preparing carboxymethyl chitosan hydrogels with different genipin concentrations (2.5%, 5%, 10% and 15%, respectively). An optimum window of chitosan cationicity (5% in our case) demonstrated potential to mitigate hypertrophic scar in wound healing by suppressing the expression of a-smooth muscle actin (a-SMA) and promoting secretion of type I matrix metalloproteinases (MMP-1). In vivo, the CMCS-5% hydrogel again showed smaller, thinner and smoother wound appearance. Moreover, the CMCS-5% sample with additional incorporation of 2% (V/V) Aloe vera gel exhibited further improved performance in scar inhibition. Overall, such findings might have important implications in chitosan-based wound dressing design for high-quality wound repair and effective scar inhibition.

Fasudil inhibits actin polymerization and collagen synthesis and induces apoptosis in human urethral scar fibroblasts via the Rho/ROCK pathway

Purpose

To examine the effects and mechanism of action of fasudil on cytoskeletal polymerization, collagen synthesis, and apoptosis in fibroblasts derived from human urethral scar tissue.

Materials and methods

Fibroblasts treated with or without transforming growth factor β1 (TGF-β1, 10 ng/mL) were incubated with fasudil (12.5, 25, 50 μmol/L) for 24 hours. Quantitative real-time polymerase chain reaction and Western blotting were used to determine the expression of Arp2, Arp3, WASP, and WAVE2. Collagen I and III protein levels were also evaluated by Western blotting. The filamentous actin cytoskeleton was examined by immunofluorescence and epifluorescence microscopy. An Annexin V-FITC/PI staining assay was used to investigate apoptosis.

Results

TGF-β1-dependent induction of actin polymerization and collagen synthesis and promotion of apoptosis were dose dependent. When compared with untreated controls, fasudil significantly decreased the expression of Arp2, Arp3, WASP, WAVE2, Collagen I, and Collagen III in cells treated with or without TGF-β1. Fasudil also promoted apoptosis in cells, irrespective of TGF-β1 treatment.

Conclusion

Irrespective of TGF-β1 activation status, fasudil suppressed actin polymerization and collagen synthesis and induced apoptosis in human urethral scar fibroblasts via the Rho/ROCK signaling pathway.

Evaluation of the Distribution of Paclitaxel After Application of a Paclitaxel-Coated Balloon in the Rabbit Urethra

INTRODUCTION

Urethral strictures are a common urologic problem that could require complex reconstructive procedures. Urethral dilatation represents a frequent practiced intervention associated with high recurrence rates. Drug-coated percutaneous angioplasty balloons (DCBs) with cytostatic drugs have been effectively used for the prevention of vascular restenosis after balloon dilatation. To reduce restenosis rates of urethral dilatation, these balloons could be used in the urethra. Nevertheless, the urothelium is different than the endothelium and these drugs may not be distributed to the outer layers of the urethra. Thus, an experiment was performed to evaluate the distribution of paclitaxel (PTX) in the rabbit urethra after the inflation of a PTX-coated balloon (PCB).

MATERIALS AND METHODS

Eleven rabbits underwent dilatation of the posterior urethra with common endoscopic balloons after urethrography. Nine of these rabbits were additionally treated with PCB. The urethras of the two control animals were removed along with three more dilated with PCB urethras immediately after the dilatation. The remaining of the urethras were removed after 24 (n = 3) and 48 hours (n = 3). The posterior segments of the urethras were evaluated with hematoxylin and eosin staining as well as with immunohistochemistry with polyclonal anti-PTX antibody.

RESULTS

The two control specimens showed denudation of the urothelium after balloon dilatations and no PTX was observed. All specimens from dilated PCB urethras showed distribution of PTX to all layers of the urethra. The specimens that were immediately removed exhibited denudation of the urothelium without any inflammation. The specimens removed at 24 and 48 hours showed mild acute inflammation.

CONCLUSION

PTX was distributed to the urothelial, submucosal, and smooth muscle layers of the normal rabbit urethra immediately after dilatation with a DCB. PTX and mild inflammation were present at the site 24 and 48 hours after the dilatation.