Ann. N.Y. Acad. Sci. ISSN 0077-8923 ANNALS OF THE NEW YORK ACADEMY OF SCIENCES Issue: Pharmaceutical Science to Improve the Human Condition: Prix Galien 2014 The development of SERI R Surgical Scaffold, an engineered biological scaffold Mark Jewell,1 William Daunch,2 Bradley Bengtson,3 and Enrico Mortarino2 1Division of Plastic Surgery, Oregon Health & Science University, Portland, Oregon. 2Allergan, Inc., Medford, Massachusetts. 3Bengtson Center for Aesthetics and Plastic Surgery and Associate Professor, Michigan State University, Grand Rapids, Michigan Address for correspondence: Mark Jewell, M.D., 10 Coburg Rd, Suite 300, Eugene, OR 97401. [email protected] The primary goal of reconstructive and revision surgery is to restore, repair, rebuild, and support damaged, weakened, or absent tissue. There are numerous approaches for soft tissue support and repair, including the use of autologous tissue, human- or animal-derived acellular dermal matrices, absorbable or permanent synthetic mesh, and, now, a new class of bioresorbable protein scaffold. Although many factors influence the choice of surgical approach and the specific product used for soft tissue support and repair, the goal is to improve long-term outcomes while minimizing complications and recurrences requiring further revisional surgery. In this review, the basic science, clinical characteristics, and clinical applications of SERI R Surgical Scaffold, a novel, engineered, highly purified silk product for soft tissue support and repair will be presented. Keywords: abdominal wall reconstruction; breast revision; highly purified silk; SERI R Surgical Scaffold; soft tissue support Introduction inconsistent thickness of autologous tissue can cre- ate challenges, including delayed wound healing and Much of what is done within the scope of recon- ischemic complications.3 In reality, there are limited structive and revision surgery is designed to restore, supplies of “expendable” tissues, and soft tissue rein- repair, rebuild, and support damaged, weakened, forcement needs may exceed donor site dimensions. or absent tissue. A variety of options for soft tis- Autologous dermal collagen or fascia grafts remain sue reinforcement currently exist, and more sur- an option to reinforce small defects. geons are utilizing these products in order to Surgeons have five main categories of nonau- achieve the best long-term outcome. A starting tologous, off-the-shelf options for soft tissue sup- point for understanding how the various soft tissue– port and repair (Table 1, Fig. 1). The mostly widely support options fit into the surgical armamentar- used of these are acellular dermal matrices (ADMs), ium begins with the basic science of biomechanical which are uniquely processed tissues derived from performance at time zero (i.e., implantation). How- human or animal sources. ADMs have been used ever, additional considerations are needed, includ- in a variety of procedures (e.g., burn injury resur- ing how the native tissue may interact with the facing, breast implant support, abdominal hernia implanted material and the risk of adverse events repair) and show promise for other aesthetic and over both the short and long terms. reconstructive purposes.4 However, their utility may Although adjunctive soft tissue support in be limited by size, strength, cost, and concerns primary procedures may decrease the risk of inad- regarding adverse events.5 Additional options for equate repair and ensuing deformities, the abil- soft tissue reinforcement include absorbable or per- ity of the human body to serve as its own donor manent synthetic mesh. Overall, these products source is countered by the risk of deformity are commonly used to provide additional support and loss of functionality at the donor site.1,2 In during breast reconstruction6–8 and during addition, the increased metabolic demands and doi: 10.1111/nyas.12886 44 Ann. N.Y. Acad. Sci. 1358 (2015) 44–55 C 2015 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals Inc. on behalf of The New York Academy of Sciences. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non.]commercial and no modifications or adaptations are made. Jewell et al. The development of SERI R Surgical Scaffold Table 1. Examples of available products for soft tissue support and repair Source Resorbable Biological Silk matrix SERI R Surgical Scaffold (Allergan, Inc., Medford, MA)25 Silk Yesa Acellular dermal matrix NA Human AlloDerm R (LifeCell Corp., Branchburg, NJ)43 Human dermis AlloMaxTM (Davol, Inc., Warwick, RI)44 Human dermis DermaMatrixTM (Synthes, West Chester, PA)45 Human dermis FlexHD R (Musculoskeletal Transplant Foundation, Edison, Human dermis NJ)46 Repriza R (Specialty Surgical Products, Inc., Victor, MT)47 Human dermis Porcine StratticeTM (LifeCell Corp.)48 Porcine dermis XCM (Kensey Nash Corp., Exton, PA)49 Porcine dermis Bovine SurgiMend R (TEI Biosciences Inc., Boston, MA)50 Bovine dermis Veritas R (Synovis, St Paul, MN)51 Bovine pericardium Synthetic Absorbable VicrylTM (Ethicon, Somerville, NJ)52 Polyglactin (copolymer of Yes; NA glycolide and lactide) PHASIXTM (Davol Inc.)53 Poly-4-hydroxybutyrate Yes; 12–18 months TIGR R Matrix (Novus Scientific, San Diego, CA)54 Fiber 1: copolymer of glycolide, Yes; 4 months (fiber lactide, and trimethylene 1); 3 years (fiber 2) carbonate Fiber2:copolymeroflactideand trimethylene carbonate Permanent, nonresorbable ProleneTM (Ethicon)55 Polypropylene No Composite Partially resorbable ProceedTM (Ethicon)56 Polypropylene + cellulose + Yes; 4 weeks polydioxanone (cellulose); 6months (polydioxanone) UltraproTM (Ethicon)57 Polypropylene + poliglecaprone Yes; 84 days 25 ParietexTM (Covidien, New Haven, CT)58 Polyester + collagen Yes; 14 days Permanent, nonresorbable DUALMESH R (W.L. Gore & Associates, Inc., Flagstaff, AZ)59 Expanded No polytetrafluoroethylene aIn an ovine model, significant absorption was noted over 24 months (Data on file, Allergan, Inc.). NA, not applicable. abdominoplasty or repair of abdominal hernias;9–13 silk product for soft tissue support and repair, will however, if synthetic mesh becomes infected or be presented. SERI Surgical Scaffold is U.S. Food extrudes, there may be significant morbidity. and Drug Administration (FDA) 510(k) cleared In this review, the basic science, clinical char- for soft tissue reinforcement where deficiencies acteristics, and clinical applications of SERI R Sur- exist. Although there are many options for soft tis- gical Scaffold, a novel, engineered, highly purified sue reinforcement, a strong, pliable, bioresorbable Ann. N.Y. Acad. Sci. 1358 (2015) 44–55 C 2015 The Authors. Annals of the New York Academy of Sciences 45 published by Wiley Periodicals Inc. on behalf of The New York Academy of Sciences. The development of SERI R Surgical Scaffold Jewell et al. Autologous Nonautologous Native tissue Biological Synthetic • Harvested from donor site • Derived from natural sources/materials • Derived from man-made materials of patient SERI® Acellular Absorbable Permanent Composite Surgical dermal • May be nonresorbable • Barrier- • May be matrix composed of coated Scaffold polyglactin or composed of synthetic • Derived from • Derived from polyglycolic polypropylene mesh ultra-purified human or or silk animal tissue polyester Human Porcine Bovine Partially Permanent resorbable nonresorbable (cadaver) • Derived from • Derived from • May be • May be dermal tissue dermal tissue • Derived from composed of composed of or small or dermal tissue polypropylene ePTFE intestine pericardium + cellulose or submucosa polyester + collagen Figure 1. Classes of soft tissue support and repair devices. ePTFE, expanded polytetrafluoroethylene. productsuchasSERISurgicalScaffoldoffersa commercial size of the lot, quality testing deter- combination of attributes that have not been for- mines properties such as appearance, linear mass, merly encountered in soft tissue support and repair evenness, cleanliness, neatness, breaking tenacity, devices. elongation at break, and cohesion. SERI Surgical Scaffold is produced from the highest grade (and Engineering of SERI Surgical Scaffold therefore most consistent) silk available, sourced from the domesticated Bombyx mori silkworm. Source and composition of silk Native (raw) silk can be described in terms of its two Differentiation of SERI Surgical Scaffold from component structures: fibroin and sericin. Fibroin is surgical suture a pure protein with a –Gly–Ala–Gly–Ala–Gly–Ser– Sericin removal achieves several purposes. Native repeat along its sequence.14 Fibroin proteins form (raw) silk lacks the sheen and drape associated with a high-volume fraction of ␤-sheet microcrystallites sericin-depleted silk. Removal of the sericin makes that provide the majority of strength and stiffness the silk “silky” and renders it more easily dyeable, to silk.15 In contrast, sericin is a mixture of proteins which is typically necessary not only for textiles, and contains a large number of amino acids with but also for colored silk sutures. Visual differences hydroxyl groups (Ser, Thr, and Tyr). Sericin forms between native (raw) and purified silk fibers are the rough outer coating of native (raw) silk that shown in Figure 2. In addition, as the silk aller- functions as an adhesive to maintain the structural gens are found in the sericin layer,17 sericin removal integrity