Risk Of Scar Formation Research Articles

Secured delivery of basic fibroblast growth factor using human serum albumin-based protein nanoparticles for enhanced wound healing and regeneration

BackgroundBasic fibroblast growth factor (bFGF) is one of the critical components accelerating angiogenesis and tissue regeneration by promoting the migration of dermal fibroblasts and endothelial cells associated with matrix formation and remodeling in wound healing process. However, clinical applications of bFGF are substantially limited by its unstable nature due to rapid decomposition under physiological microenvironment.ResultsIn this study, we present the bFGF-loaded human serum albumin nanoparticles (HSA-bFGF NPs) as a means of enhanced stability and sustained release platform during tissue regeneration. Spherical shape of the HSA-bFGF NPs with uniform size distribution (polydispersity index < 0.2) is obtained via a simple desolvation and crosslinking process. The HSA-bFGF NPs securely load and release the intact soluble bFGF proteins, thereby significantly enhancing the proliferation and migration activity of human dermal fibroblasts. Myofibroblast-related genes and proteins were also significantly down-regulated, indicating decrease in risk of scar formation. Furthermore, wound healing is accelerated while achieving a highly organized extracellular matrix and enhanced angiogenesis in vivo.ConclusionConsequently, the HSA-bFGF NPs are suggested not only as a delivery vehicle but also as a protein stabilizer for effective wound healing and tissue regeneration.

The feasibility of negative pressure wound therapy versus standard dressings in paediatric hand and foot burns protocol: a pilot, single-centre, randomised control trial

IntroductionThe goal of paediatric hand and foot burn management is hypertrophic scar and/or contracture prevention. The risk of scar formation may be minimised by integrating negative pressure wound therapy (NPWT) as an acute care adjunct as it decreases the time to re-epithelialisation. NPWT has known associated therapeutic burden; however, this burden is hypothesised to be outweighed by an increased likelihood of hypertrophic scar prevention. This study will assess the feasibility, acceptability and safety of NPWT in paediatric hand and foot burns with secondary outcomes of time to re-epithelialisation, pain, itch, cost and scar formation.Methods and analysisThis is a single-site, pilot randomised control trial. Participants must be aged ≤ 16 years, otherwise well and managed within 24 h of sustaining either a hand or foot burn. Thirty participants will be randomised to either standard care (Mepitel®—a silicone wound interface contact dressing—and ACTICOAT™—a nanocrystalline silver-impregnated dressing) or standard care plus NPWT. Patients will be reviewed until 3 months post-burn wound re-epithelialisation, with measurements taken at dressing changes to assess primary and secondary outcomes. Surveys, randomisation and data storage will be done via online platforms and physical data storage collated at the Centre for Children’s Health Research, Brisbane, Australia. Analysis will be performed using the Stata statistical software.Ethics and disseminationQueensland Health and Griffith University Human Research ethics approval including a site-specific assessment was obtained. The findings of this study will be disseminated through clinical meetings, conference presentations and peer reviewed journals.Trial registrationRegistered with the Australian and New Zealand Clinical Trials Registry (ACTRN12622000044729, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=381890&isReview=true, registered 17/01/2022).

Design of New Concept of Knitted Hernia Implant.

A knitted implant, unilaterally modified with plasma-assisted chemical-vapor deposition (PACVD), and with a nano-layer of fluorine derivative supplementation, for reducing the risk of complications related to adhesions, and the formation of a thick postoperative scar was prepared. The biological evaluation of designed or modified medical devices is the main aspect of preclinical research. If such studies use a medical device with prolonged contact with connective tissue (more than 30 days), biocompatibility studies require a safety assessment in terms of toxicity in vitro and in vivo, allergenicity, irritation, and cancerogenicity, reproductive and developmental toxicity. The ultimate aspect of biological evaluation is biofunctionality, and evaluation of the local tissue response after implantation, resulting in the determination of all aspects of local biocompatibility with the implemented synthetic material. The implantation of PACVD-modified materials in muscle allows us to estimate the local irritation effect on the connective tissue, determining the risk of scar formation, whereas implantation of the above-mentioned knitted fabric into the abdominal wall, assists with evaluating the risk of fistula formation—the main post-surgical complications. The research aimed to evaluate the local reaction of the soft tissues after the implantation of the knitted implants modified with PACVD of the fluoropolymer in the nanostuctural form. The local effect that occurred during the implantation of the designed implants was quantitatively and qualitatively evaluated when PACVD unmodified (reference), and modified medical devices were implanted in the abdominal cavity (intra-abdominal position) for 12 or into the muscles for 56 weeks. The comparative semi-quantitative histological assessment included the severity of inflammatory cells (multinucleated cells, lymphocytes, plasma cells, macrophages, giant cells) and the tissue response (necrosis, neovascularization, fibrosis, and fat infiltration) on a five-point scale. The knitted implants modified by PACVD did not indicate cumulative tissue response when they were implanted in the muscle and intra-abdominally with direct contact with the viscera. They reduced local tissue reaction (score −2.71 after 56 weeks of the implantation) and internal organ adhesion (irritation score −2.01 and adhesion susceptibility −0.3 after 12 weeks of the implantation) compared with the reference (unmodified by PACVD) knitted implant, which had an identical structure and was made of the same source.

Gentle cyclic straining of human fibroblasts on electrospun scaffolds enhances their regenerative potential

The extracellular matrix of fascia-like tissues is a resilient network of collagenous fibers that withstand the forces of daily life. When overstretched, the matrix may tear, with serious consequences like pelvic organ prolapse (POP). Synthetic implants can provide mechanical support and evoke a host response that induces new matrix production, thus reinforcing the fascia. However, there is considerable risk of scar formation and tissue contraction which result in severe complications. Matrix producing fibroblasts are both mechanosensitive and contractile; their behavior depends on the implant’s surface texture and mechanical straining. Here we investigate the effect of both in a newly-designed experimental setting.Electrospun scaffolds of Nylon and PLGA/PCL and a non-porous PLGA/PCL film were clamped like a drumhead and seeded with fibroblasts of POP patients. Upon confluency, scaffolds were cyclically strained for 24 or 72 h at 10% and 0.2 Hz, mimicking gentle breathing. Non-loading condition was control. Strained fibroblasts loosened their actin-fibers, thereby preventing myofibroblastic differentiation. Mechanical loading upregulated genes involved in matrix synthesis (collagen I, III, V and elastin), matrix remodeling (α-SMA, TGF-β1, MMP-2) and inflammation (COX-2, TNF-α, IL8, IL1-β). Collagen genes were expressed earlier under mechanical loading and the ratio of I/III collagen increased. Matrix synthesis and remodeling were stronger on the electrospun scaffolds, while inflammation was more prominent on the non-porous film. Our findings indicate that mechanical straining enhances the regenerative potential of fibroblasts for the regeneration of fascia-type tissues and limit the risk of scar tissue formation. These effects are stronger on an electrospun texture. Statement of significancePelvic organ prolapsed is a dysfunctional disease in female pelvic floor that can reduce the quality of life women. Currently, trans-vaginal knitted meshes are used to anatomically correct the dysfunctional tissues. However, the meshes can create sever adverse complications in some patients (e.g. chronic pain) in longer-term. As an alternative, we developed nanofibrous matrices by electrospinning based on different materials. We designed an in-vitro culture system and subjected cell-seeded matrices to cyclic mechanical loading. Results revealed that gentle straining of POP-cells on electrospun matrices, advances their regenerative potential at morphological and gene expression levels. Our findings, provide a proof-of-concept for using electrospun matrices as an alternative implant for pelvic floor repair, given that the parameters are designed efficiently and safely.

Interventional bleeding, hematoma and scar-formation after vacuum-biopsy under stereotactic guidance: Mammotome®-system 11g/8g vs. ATEC®-system 12g/9g

To evaluate prospectively the correlation of scar-formations after vacuum-assisted biopsy with different systems and needle-sizes and interventional bleeding/post-interventional hematoma. Between 01/2008 and 12/2009, 479 patients underwent vacuum-assisted biopsy under stereotactic-guidance, using the Mammotome(®)-system with 11/8-gauge and ATEC(®)-system with 12/9-gauge, whereas in 178 cases with representative benign histology no surgical-biopsy after vacuum-assisted biopsy was performed and at least a 2-plane-follow-up-mammogram after 6 month post-vacuum-assisted biopsy was available. Bleeding during intervention, hematoma post-intervention and scar-tissue was scored as minimal and moderate/severe. Statistical analysis included Chi-Square-trend-test, p-value <0.05 was considered to be significant. Significantly more bleedings and post-interventional hematomas for 8-gauge-Mammotome(®)-system vs. 11-gauge-Mammotome(®)-system (41.9% vs. 8.4%, p<0.001/35.5% vs. 16.7%, p=0.029), no significant-differences for the ATEC(®)-systems 9-gauge vs. 12-gauge (26.9% vs. 29.7%, p=0.799/42.3% vs. 43.2%, p=0.596). 11-gauge-Mammotome(®)-system vs. ATEC(®)-12-gauge-system revealed significantly less bleedings/hematomas (8.4% vs. 29.7%, p=0.015/16.7% vs. 43.2%, p=0.001), no significant differences for the large-systems (p=0.135/p=0.352). Follow-up of Mammotome(®)-11/8-gauge-system system has shown 13.1/16.1% minimal scar-formation and 1.2/3.2% moderate/severe scars, whereas ATEC(®)-12/9-gauge-system has shown 10.8/3.8% minimal scar-formation and 0/11.5% moderate/severe scars, no significant differences. No significant difference was found when comparing Mammotome(®)-11/8-g-systems vs. ATEC(®)-12/9-g-systems (p=0.609/p=0.823). There was also no correlation between risk of scar-formation after occurrence of bleeding or hematoma with any examined VAB-system or any needle size in this study (p=0.800). Using larger needle-sizes significantly (Mammotome(®))/not significant for ATEC(®)) more interventional bleedings and post-interventional hematomas were detected, only a tendency concerning scar-formation.

Comparison of the 532-nm KTP and 1064-nm Nd:YAG lasers for the treatment of cherry angiomas

Background: Laser therapy is the treatment of choice for cherry angiomas since it is more effective and has better cosmetic results. There is no comparative study about the treatment efficacies with KTP and Nd:YAG lasers for cherry angiomas. Objective: To compare the efficacy and side effects of 532-nm KTP and 1064-nm Nd:YAG lasers for the treatment of cherry angiomas. Methods: Two comparable lesions of the same patient were chosen. One of them was treated with the KTP laser while the other was treated with the Nd:YAG laser. Sessions were repeated every 4 weeks until complete clearance was achieved. Side effects were evaluated using a severity scale (0 to 4). Results: The number of sessions was significantly higher with the KTP than with the Nd:YAG laser (p = 0.002). Erythema, edema, pain and scar formation were higher in the Nd:YAG laser group (erythema: p = 0.001; edema: p < 0.001; pain: p < 0.001; scar: p < 0.001). The hyperpigmentation rate was statistically higher with the KTP laser (p = 0.01). Conclusion: Both KTP and Nd:YAG lasers were found to be effective methods. The Nd:YAG laser offered fewer treatment sessions, but a higher risk of scar formation. The KTP laser seems more advantageous, but in dark-skinned patients the Nd:YAG laser may be preferable.

Lipid-A-antibodies--indicators for the risk of renal scarring in children with urinary tract infection.

The levels of IgG- and IgM-antibodies against lipid A were determined by an ultramicro-ELISA in 54 children between 2 months and 13 years of age with non-obstructive urinary tract infections at the onset of the infection and subsequently after 3, 6 and 12 months. Children older than 2 years who later developed renal scarring as shown by intravenous pyelograms had higher levels of IgG antibodies than those without scars. This correlation was not found in children younger than 2 years of age. IgM-antibody levels did not correlate with the risk of scar formation. We conclude that the IgG-antibody level against lipid A is a useful indicator for early recognition of children over the age of two years who will later develop renal scars. The ultramicro-ELISA technique makes screening for children at risk possible at a low cost.