For those publications discussing use of Galatea surgical scaffolds (GalaFLEX®, GalaFLEX 3D™ or GalaFLEX 3DR™), the FDA does not consider the use of these products as described in the publications to be within the cleared indications for use for each device. Significant safety risks or safety concerns associated with the use of Galatea scaffolds known to the manufacturer are described in the Instructions for Use for each of those devices.  

PHA Applications: Addressing the price performance issue: I. Tissue engineering.

Category: Review
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Simon F Williams, PhD; David P Martin, PhD; Daniel M Horowitz, PhD; and Oliver P Peoples, PhD

International Journal of Biological Macromolecules 25(1-3):111-21.1999

Link to Publication: https://www.ncbi.nlm.nih.gov/pubmed/10416657

ABSTRACT

This paper describes the development of medical applications for polyhydroxyalkanoates (PHAs), a class of natural polymers with a wide range of thermoplastic properties. Methods are described for preparing PHAs with high purity, modifying these materials to change their surface and degradation properties, and methods for fabricating them into different forms, including tissue engineering scaffolds. Preliminary reports characterizing their in vivo behavior are given, as well as methods for using the natural polymers in tissue engineering applications.

DISCLOSURES

Dr. Simon Williams is a Consultant to Tepha, Inc. and a member of the Tepha Board of Directors. Dr. David Martin is the Chief Scientific Officer of Tepha, Inc.

Applications of PHAs in Medicine and Pharmacy.

Category: Review
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Simon F. Williams, PhD and David P. Martin, PhD

Biopolymers Online 2005

Link to Publication: https://onlinelibrary.wiley.com/doi/10.1002/3527600035.bpol4004

ABSTRACT

Polyhydroxyalkanoates (PHAs) are a class of naturally occurring polyesters that are produced by a wide variety of different microorganisms (Steinb¸chel,1991). Although they are derived biologically, the structures of these polymers bear a fairly close resemblance to some of the synthetic absorbable polymers currently used in medical applications. Owing to their limited availability, the PHAs have remained largely unexplored, yet these polymers offer an extensive range of properties that extend far beyond those currently offered by their synthetics counter-parts.

DISCLOSURES

Dr. Simon Williams is a Consultant to Tepha, Inc. and a member of the Tepha Board of Directors. Dr. David Martin is the Chief Scientific Officer of Tepha, Inc.

Medical Applications of Poly-4-Hydroxybutyrate: a strong flexible absorbable biomaterial.

Category: Review
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Simon F. Williams, PhD and David P. Martin, PhD

Biochemical Engineering Journal 16 (2):97-105.2003

Link to Publication: https://www.sciencedirect.com/science/article/abs/pii/S1369703X03000408

ABSTRACT

Poly-4-hydroxybutyrate (P4HB) is being developed as a new absorbable material for implantable medical applications. P4HB promises to open up new opportunities for the development of medical applications by offering a new set of properties that are not currently available. The absorbable biomaterial is strong yet flexible, and degrades in vivo at least in part by a surface erosion process. While the chemical structure of P4HB is similar to that of current absorbable polyesters used in implantable medical products, P4HB is produced by a fermentation process rather than through a chemical synthesis. P4HB is a thermoplastic material that can be processed using standard plastics processing techniques, such as solution casting or melt extrusion.
The strength of P4HB fibers prepared by melt extrusion compare well with that of traditional suturing materials, however, P4HB is typically more flexible. P4HB should find use in a wide variety of medical fields such as cardiovascular, wound healing, orthopedic, drug delivery, and tissue engineering applications. This paper describes some of the basic properties of P4HB and several of its potential applications in medicine.

DISCLOSURES

Dr. Simon Williams is a Consultant to Tepha, Inc. and a member of the Tepha Board of Directors. Dr. David Martin is the Chief Scientific Officer of Tepha, Inc.

Biomechanical Properties of Superficial Musculoaponeurotic System Tissue With vs. Without Reinforcement With Poly-4-hydroxybutyric Acid Absorbable Mesh

Category:
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Patrick C. Angelos, MD; Tara E. Brennan, MD; Dean M. Toriumi, MD

JAMA Facial Plastic Surgery 16(3):199-205.

May 2014

Full Article

ABSTRACT

It is unknown whether poly-4-hydroxybutyric acid (P4HB)-reinforced superficial musculoaponeurotic system tissue (SMAS) plication techniques will support SMAS imbrication and plication and potentially improve outcomes in rhytidectomy.

Objectives: To evaluate the biomechanical properties (tissue breaking strength, suture tearing force, and stress relaxation) of the SMAS with vs without reinforcement with P4HB absorbable mesh and to correlate these results with potential clinical applications.

Design: In a cadaver study at an academic setting, 12 fresh frozen cadaver heads were used. Rhytidectomy incisions were made, and the SMAS was harvested and prepared for strength and stress testing using an Instron device.

Outcomes: Tissue breaking strength and suture tearing force were analyzed. Stress relaxation test results were also assessed. The results of the SMAS samples alone were compared with those reinforced with P4HB absorbable mesh.

Results: Overall, there were significant differences noted in tissue breaking strength and suture tearing force between the 2 groups. When the SMAS was reinforced with absorbable mesh, significant improvements were observed in tissue breaking strength (P < .001) and suture tearing force (P < .003). In addition, less variability was demonstrated in the maximum tensile load-bearing quality of the SMAS when the repair was reinforced with P4HB.

Conclusions and Relevance: Reinforcement with P4HB absorbable mesh improves tissue breaking strength and suture tearing force in cadaveric SMAS. It also reduces the variability in load vs displacement seen among samples tested. These data suggest that P4HB-reinforced SMAS imbrication would support higher loads and provide more consistent, long-lasting SMAS support among patients undergoing rhytidectomy. Further studies are needed to correlate these data with clinical outcomes in rhytidectomy.

DISCLOSURES

Authors: Dr. Dean Toriumi is a consultant with Galatea Surgical, Inc.

Characterization of poly-4-hydroxybutyrate mesh for hernia repair applications

Category: Pre-Clinical
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David P. Martin, PhD; Amit Badhwar, PhD; Devang V. Shah, PhD; Said Rizik, MS; Stephen N. Eldridge, MS; Darcy H. Gagne, BS; Amit Ganatra, MS; Roger E. Darois, BEng; Simon F. Williams, PhD; Hsin-Chien Tai, PhD; and Jeffrey R. Scott, PhD

Journal of Surgical Research 184(2):766-773.2013

Link to Publication: https://www.ncbi.nlm.nih.gov/pubmed/23582230

ABSTRACT

Background: Phasix mesh is a fully resorbable implant for soft tissue reconstruction made from knitted poly-4-hydroxybutyrate monofilament fibers. The objectives of this study were to characterize the in vitro and in vivo mechanical and resorption properties of Phasix mesh over time, and to assess the functional performance in a porcine model of abdominal hernia repair.

Materials and Methods: We evaluated accelerated in vitro degradation of Phasix mesh in 3 mol/L HCl through 120 h incubation. We also evaluated functional performance after repair of a surgically created abdominal hernia defect in a porcine model through 72 wk. Mechanical and molecular weight (MW) properties were fully characterized in both studies over time.

Results: Phasix mesh demonstrated a significant reduction in mechanical strength and MW over 120 h in the accelerated degradation in vitro test. In vivo, the Phasix mesh repair demonstrated 80%, 65%, 58%, 37%, and 18% greater strength, compared with native abdominal wall at 8, 16, 32, and 48 wk post-implantation, respectively, and comparable repair strength at 72 wk post-implantation despite a significant reduction in mesh MW over time.

Conclusions: Both in vitro and in vivo data suggest that Phasix mesh provides a durable scaffold for mechanical reinforcement of soft tissue. Furthermore, a Phasix mesh surgical defect repair in a large animal model demonstrated successful transfer of load bearing from the mesh to the repaired abdominal wall, thereby successfully returning the mechanical properties of repaired host tissue to its native state over an extended time period.

DISCLOSURES

Dr. Simon Williams is a Consultant to Tepha, Inc. and a member of the Tepha Board of Directors. Dr. David Martin is the Chief Scientific Officer of Tepha, Inc. Said Rizik, MS, Amit Ganatra, MS, Jeffrey R. Scott, PhD are employees of Tepha, Inc.

Characterization of the Mechanical Strength, Resorption Properties, and Histologic Characteristics of a Fully Absorbable Material (Poly-4-hydroxybutyrate—PHASIX Mesh) in a Porcine Model of Hernia Repair

Category: Pre-Clinical
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Corey R. Deeken, PhD and Brent D. Matthews, MD

ISRN Surgery 2013

Link to Publication: https://www.ncbi.nlm.nih.gov/pubmed/23781348

ABSTRACT

Purpose: Poly-4-hydroxybutyrate (P4HB) is a naturally derived, absorbable polymer. P4HB has been manufactured into PHASIX Mesh and P4HB Plug designs for soft tissue repair. The objective of this study was to evaluate mechanical strength, resorption properties, and histologic characteristics in a porcine model.

Methods: Bilateral defects were created in the abdominal wall of n = 20 Yucatan minipigs and repaired in a bridged fashion with PHASIX Mesh or P4HB Plug fixated with SorbaFix or permanent suture, respectively. Mechanical strength, resorption properties, and histologic characteristics were evaluated at 6, 12, 26, and 52 weeks (n = 5 each).

Results: PHASIX Mesh and P4HB Plug repairs exhibited similar burst strength, stiffness, and molecular weight at all time points, with no significant differences detected between the two devices (P > 0.05). PHASIX Mesh and P4HB Plug repairs also demonstrated significantly greater burst strength and stiffness than native abdominal wall at all time points (P < 0.05), and material resorption increased significantly over time (P < 0.001). Inflammatory infiltrates were mononuclear, and both devices exhibited mild to moderate granulation tissue/vascularization.

Conclusions: PHASIX Mesh and P4HB Plug demonstrated significant mechanical strength compared to native abdominal wall, despite significant material resorption over time. Histological assessment revealed a comparable mild inflammatory response and mild to moderate granulation tissue/vascularization.

Indications for Use

GalaFLEX, GalaFLEX 3D and GalaFLEX 3DR scaffolds are indicated for use as bioresorbable scaffolds for soft tissue support and to repair, elevate, and reinforce deficiencies where weakness or voids exist that require the addition of material to obtain the desired surgical outcome. This includes reinforcement of soft tissue in plastic and reconstructive surgery, and general soft tissue reconstruction. These products, referred to as Galatea scaffolds, are also indicated for the repair of fascial defects that require the addition of a reinforcing or bridging material to obtain the desired surgical result.

Important Safety Information

Possible complications following implantation of Galatea scaffolds include infection, seroma, pain, scaffold migration, wound dehiscence, hemorrhage, adhesions, hematoma, inflammation, extrusion and recurrence of the soft tissue defect. The safety and product use of Galatea scaffolds for patients with hypersensitivities to the antibiotics kanamycin sulfate and tetracycline hydrochloride is unknown. Galatea scaffolds have not been studied for use in breast reconstructive surgeries. The safety and effectiveness of Galatea scaffolds in neural tissue and in cardiovascular tissue has not been established. The safety and effectiveness of Galatea scaffolds in pediatric use has not been established. Consult the specific Galatea scaffold Instructions for Use for complete prescribing information, including its indications for use, warnings and precautions.