Nanofibrous structured biomimetic strategies for skin tissue regeneration

Mimicking porous topography of natural extracellular matrix is advantageous for successful regeneration of damaged tissues or organs. Nanotechnology being one of the most promising and growing technology today shows an extremely huge potential in the field of tissue engineering. Nanofibrous structures that mimic the native extracellular matrix and promote the adhesion of various cells are being developed as tissue‐engineered scaffolds for skin, bone, vasculature, heart, cornea, nervous system, and other tissues. A range of novel biocomposite materials has been developed to enhance the bioactive or therapeutic properties of these nanofibrous scaffolds via surface modifications, including the immobilization of functional cell‐adhesive ligands and bioactive molecules such as drugs, enzymes, and cytokines. In skin tissue engineering, usage of allogeneic skin is avoided to reestablish physiological continuity and also to address the challenge of curing acute and chronic wounds, which remains as the area of exploration with various biomimetic approaches. Two‐dimensional, three‐dimensional scaffolds and stem cells are presently used as dermal regeneration templates for the treatment of full‐thickness skin defects resulting from injuries and severe burns. The present review elaborates specifically on the fabrication of nanofibrous structured strategies for wound dressings, wound healing, and controlled release of growth factors for skin tissue regeneration.     

Subcutaneous drain insertion in patients with post-operative extensive subcutaneous surgical emphysema: a single centre experience

Objective

Extensive surgical subcutaneous emphysema (ESE) albeit a benign condition could cause patients distress and in many cases temporary vision impairment. We describe the role and value of early subcutaneous drain insertion (SCD) in the management of ESE and patients’ experience in this cohort study.

Methods

Extensive surgical subcutaneous emphysema is that which extends to the neck and/or the peri-orbital region. A cohort study of a prospectively collected data was conducted between December 2009 and January 2012. All patients with extensive post-operative surgical emphysema who had SCD (size ≥24 French gauge) were included.

Results

1069 thoracic procedures were performed. 21 patients (1.96 %) were diagnosed with extensive surgical emphysema, there were 16 males, median age was 65 (54–82 years). There were 16 VATS and 5 open procedures. All patients had chest surgical emphysema, 16 patients had peri-orbital and neck swelling and 5 had neck swelling. Surgical emphysema occurred within a median of 3 days post-operatively. 14 (67 %) patients had 1 subcutaneous drain inserted, and 7 (33 %) had bilateral SCD insertion (1 drain each side). 19 (90 %) patients experienced improvement of their symptoms with resolution of neck and peri-orbital swelling within 1 day of SCD insertion, 2 patients had their symptoms improved within 2 days. All patients were satisfied with the outcome following insertion of SCD.

Conclusions

ESE should always be investigated and treated promptly. Early SCD insertion has a valuable role in the management of ESE with improvement of patients’ experience.     

N-hydroxy-pyrroline modification of verapamil exhibits antioxidant protection of the heart against ischemia/reperfusion-induced cardiac dysfunction without compromising its calcium antagonistic activity

Any clinical intervention (e.g., coronary angioplasty, thrombolysis) used to reintroduce blood flow to an ischemic region of the myocardium is accompanied by a complex enzymatic cascade of reactions resulting in severe injury to the heart, termed myocardial ischemia/reperfusion (I/R) injury. In this study, we evaluated the ability of H-3010 (1-hydroxy-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrole-3-carboxylic acid (2-(3,4-dimethoxyphenyl)-5-([2-(3,4-dimethoxyphenyl)ethyl]-methylamino)-2-isopropylpentyl)-amide), a pyrroline modification of verapamil (2-(3,4-dimethoxyphenyl)-5-[2-(3,4-dimethoxyphenyl)ethylmethyl-amino]-2-(1-methylethyl)pentanenitrile), to protect the heart against I/R-mediated injury. Isolated perfused rat hearts pretreated with verapamil and H-3010 were subjected to 30 min of global no-flow ischemia followed by 45 min of reperfusion. The recovery (expressed as a percentage of preischemic baseline) in contractile function (left ventricular developed pressure) of hearts subjected to I/R was significantly higher in hearts treated with H-3010 at 5 microM (51.0 +/- 6.4%) as well as at 50 microM (75.1 +/- 7.4%) as compared with verapamil at 5 microM (32.2 +/- 3.7%) or untreated control hearts (18.1 +/- 2.8%). Creatine kinase release was significantly attenuated in hearts treated with H-3010 (45.7 +/- 4.5 U/liter) as compared with untreated controls (131.5 +/- 6.4 U/liter). Similar trends were also observed for lactate dehydrogenase release as well. A marked reduction in percent area of infarction was observed in the H-3010 group (11.7 +/- 1.6%) compared with verapamil (25.1 +/- 2.9%) and control (41.3 +/- 1.9%) groups. Additional in vitro studies showed a marked decrease in reactive oxygen species generation with H-3010. In conclusion, our data clearly demonstrated that the verapamil derivative, H-3010, significantly decreased I/R-induced cardiac dysfunction. This can be attributed to the combined benefits of the pyrroline moiety (antioxidant) and the parent verapamil component (antiarrhythmic) in the protection of the heart from I/R-induced injury.