scholarly journals Evaluation of Bi-Layer Silk Fibroin Grafts for Penile Tunica Albuginea Repair in a Rabbit Corporoplasty Model

2021 ◽  
Vol 9 ◽  
Author(s):  
Gokhan Gundogdu ◽  
Zhamshid Okhunov ◽  
Stephanie Starek ◽  
Faith Veneri ◽  
Hazem Orabi ◽  
...  
Keyword(s):  
Silk Fibroin ◽  
Tunica Albuginea ◽  
Donor Site ◽  
Collagen Type I ◽  
Donor Site Morbidity ◽  
Type I ◽  
New Zealand White Rabbits ◽  
Point Evaluations ◽  
Intestinal Submucosa ◽  
Tissue Grafts

The use of autologous tissue grafts for tunica albuginea repair in Peyronie’s disease and congenital chordee is often restricted by limited tissue availability and donor site morbidity, therefore new biomaterial options are needed. In this study, bi-layer silk fibroin (BLSF) scaffolds were investigated to support functional tissue regeneration of tunica albuginea in a rabbit corporoplasty model. Eighteen adult male, New Zealand white rabbits were randomized to nonsurgical controls (NSC, N = 3), or subjected to corporoplasty with BLSF grafts (N = 5); decellularized small intestinal submucosa (SIS) matrices (N = 5); or autologous tunica vaginalis (TV) flaps (N = 5). End-point evaluations were cavernosography, cavernosometry, histological, immunohistochemical, and histomorphometric assessments. Maximum intracorporal pressures (ICP) following papaverine-induced erection were similar between all groups. Eighty percent of rabbits repaired with BLSF scaffolds or TV flaps achieved full rigid erections, compared to 40% of SIS reconstructed animals. Five-minute peak erections were maintained in 60% of BLSF rabbits, compared to 20% of SIS and TV flap reconstructed rabbits. Graft perforation occurred in 60% of TV group at maximum ICP compared to 20% of BLSF cohort. Neotissues supported by SIS and BLSF scaffolds were composed of collagen type I and elastin fibers similar to NSC. SIS and TV flaps showed significantly elevated levels of corporal fibrosis relative to NSC with a corresponding decrease in corporal smooth muscle cells expressing contractile proteins. BLSF biomaterials represent emerging platforms for corporoplasty and produce superior functional and histological outcomes in comparison to TV flaps and SIS matrices for tunica albuginea repair.

Bioengineered neo-corneal endothelium using collagen type-I coated silk fibroin film

2015 ◽  
Vol 136 ◽  
pp. 394-401 ◽  
Author(s):  
Eun Young Kim ◽  
Nirmalya Tripathy ◽  
Sun Ah Cho ◽  
Choun-Ki Joo ◽  
Dongwon Lee ◽  
...  
Keyword(s):  
Silk Fibroin ◽  
Corneal Endothelium ◽  
Collagen Type ◽  
Collagen Type I ◽  
Type I ◽  
Silk Fibroin Film

scholarly journals Evaluation of Bi-Layer Silk Fibroin Grafts for Tubular Ureteroplasty in a Porcine Defect Model

2021 ◽  
Vol 9 ◽  
Author(s):  
Gokhan Gundogdu ◽  
Zhamshid Okhunov ◽  
Vivian Cristofaro ◽  
Stephanie Starek ◽  
Faith Veneri ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Silk Fibroin ◽  
Ex Vivo ◽  
Degradation Kinetics ◽  
Smooth Muscle Actin ◽  
Donor Site ◽  
Donor Site Morbidity ◽  
Stricture Formation ◽  
Ureteral Reconstruction

Ureteral reconstruction with autologous tissue grafts is often limited by tissue availability and donor site morbidity. This study investigates the performance of acellular, bi-layer silk fibroin (BLSF) scaffolds in a porcine model of ureteroplasty. Tubular ureteroplasty with BLSF grafts in combination with transient stenting for 8 weeks was performed in adult female, Yucatan, mini-swine (N = 5). Animals were maintained for 12 weeks post-op with imaging of neoconduits using ultrasonography and retrograde ureteropyelography carried out at 2 and 4 weeks intervals. End-point analyses of ureteral neotissues and unoperated controls included histological, immunohistochemical (IHC), histomorphometric evaluations as well as ex vivo functional assessments of contraction/relaxation. All animals survived until scheduled euthanasia and displayed mild hydronephrosis (Grades 1-2) in reconstructed collecting systems during the 8 weeks stenting period with one animal presenting with a persistent subcutaneous fistula at 2 weeks post-op. By 12 weeks of scaffold implantation, unstented neoconduits led to severe hydronephrosis (Grade 4) and stricture formation in the interior of graft sites in 80% of swine. Bulk scaffold extrusion into the distal ureter was also apparent in 60% of swine contributing to ureteral obstruction. However, histological and IHC analyses revealed the formation of innervated, vascularized neotissues with a-smooth muscle actin+ and SM22α+ smooth muscle bundles as well as uroplakin 3A+ and pan-cytokeratin + urothelium. Ex vivo contractility and relaxation responses of neotissues were similar to unoperated control segments. BLSF biomaterials represent emerging platforms for tubular ureteroplasty, however further optimization is needed to improve in vivo degradation kinetics and mitigate stricture formation.

scholarly journals A review and critical appraisal of central axis flaps in axillary and elbow contractures

2017 ◽  
Vol 5 ◽  
Author(s):  
Durga Karki ◽  
Rajeev B. Ahuja
Keyword(s):  
Daily Living ◽  
Critical Appraisal ◽  
Donor Site ◽  
Donor Site Morbidity ◽  
Central Axis ◽  
Type I ◽  
Comprehensive Review ◽  
Contracture Release ◽  
Cubital Fossa

Abstract Contractures of the axilla and elbow can produce a significant impact on quality of life by reducing the ability to perform activities of daily living. Varieties of techniques are available for resurfacing defects following contracture release but graft or flap loss, donor-site morbidity, esthetics, and recurrences are still challenges for reconstructive surgeons. Central axis “propeller” flaps based on a random, subcutaneous pedicle were first described for axillary and elbow contractures to deploy the unburnt skin of axillary dome in type I and II contractures (Kurtzman and Stern) by moving them 90° to straddle the contracting bands. This strategy provided better esthetics and avoided prolonged splinting. Over more than two decades, there have been several design modifications of these flaps with extended applications to cubital fossa. A comprehensive review of published literature on the topic is presented to discuss classifications, design modifications, and applications of such flaps in managing axillary and elbow contractures.

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