Tendon/Ligament Repair Utilizing Stromal Derived Factor Infused Alginate Coated Collagen Fibers

Transcription

1 Tendon/Ligament Repair Utilizing Stromal Derived Factor Infused Alginate Coated Collagen Fibers Mario Rossi, Anne Tucker, Brian Ziola Advisors: Dr. Yawen Li, Dr. Therese Bou-Akl, Dr. Tristan Maerz, Meagan Salisbury Team Collagen Constructs

2 Problem Identification Meetings with Dr. Bou-Akl & Beaumont to determine clinically relevant needs Researched literature for needs and refinement Observed needs: Orthopedic need for tendon/ligament injury repair

3 Need Statement There is a need for a greater tensile strength, anatomically correct solution for tendon/ligament injury repair

4 Current Solutions Non-surgical Surgical Market Analysis: Suture, graft Orthopaedic soft tissue market size- $5B Growth: $9.39B by 2024 Stakeholder Analysis: Influential stakeholders: Patients, athletes, orthopaedic surgeons, insurance providers Decision makers: Surgeons and insurance providers

5 Tissue Engineering Current studies use cells (usually stem cells) seeded on scaffold with or without mechanical stimulation Few stem cell-based tendon/ligament tissue engineering strategies translated to clinical trials Primarily due to: Significant cost Technical challenges Regulatory hurdles Time-intensive nature of autologous and allogeneic stem cell harvest 5

6 Project Overview Objective: Design a biomimetic scaffold that attracts stem cells by the release of SDF-1 to replace damaged tendons/ligaments as a more effective method of tendon/ligament repair Design Electrospun collagen coated with alginate containing SDF-1 will attract MSCs to the scaffold

7 Hypothesis A biocompatible fibrous collagen scaffold incorporating SDF-1 will induce the migration of MSCs in vitro 7

8 Experimental Setup Electrospin collagen samples Electrospinning Process Biocompatibility Testing Biocompatibility Set-Up Cross-link samples Alginate Coating With SDF-1 Mechanical Testing Release Study of SDF-1 MSC Migration Study

9 Testing and Results- Environmental Scanning Electron Microscope (ESEM) Characterization Cross-linking merges fiber strands Electrospun collagen fibers After cross-linking

10 Testing and Results- Biocompatibility Study Cell numbers on each scaffold quantified using alamarblue assay Cell attachment and proliferation in 3 weeks Day 22 Sample stained with Calcein AM and ethidium homodimer to show live (green) and dead (red) cells

11 Testing and Results- SDF-1 Release Study Release profile measured using Enzyme-linked Immunosorbent Assay (ELISA) 62% of 24-hour payload released in the first 4 hours

12 Testing and Results- Mechanical Testing Stress/strain measured using mechanical tester in ESEM Elastic Modulus: 4MPa 12MPa Ultimate tensile strength: 1.6 MPa 2.9 MPa

13 Testing and Results- Migration Study Fluorescence increases with increasing cell number N=2 Sample

14 Testing and Results- Migration Study Cont. Positive control significantly more effective in inducing MSC migration (P<.01) Migration in negative control likely due to insufficient attachment period Sample on bottom of well caused lower fluorescence

15 Division of Tasks

16 Timeline

17 Summary and Future Work Achieved a biocompatible scaffold that SDF-1 is released from the alginate coating Optimize cross-linking to achieve greater mechanical strength Further release testing to determine the effective concentration of SDF-1 to include in alginate coating to achieve a release of 100 ng in 24 hours to promote MSC migration

18 Acknowledgements We would like to thank Angelica Guardia and our advisors for their time and dedication

19 References By Procedure (Rotator Cuff Repair, Epicondylitis, Achilles Tendinosis Repair, Pelvic Organ Prolapsed, Gluteal Tendon, Cruciate Ligaments Repair, Hip Arthroscopy, Biceps Tenodesis), By Injury Location (Knee, Shoulder, Hip, Small Joints), And Trend Analysis From 2013 To "Orthopedic Soft Tissue Repair Market Size, Share Report, 2024." Orthopedic Soft Tissue Repair Market Size, Share Report, N.p., Oct Web. 27 Oct Shearn, Jason T. et al. Tendon Tissue Engineering: Progress, Challenges, and Translation to the Clinic. Journal of musculoskeletal & neuronal interactions 11.2 (2011): Print. "Research and Markets Adds Report: Orthopedic Soft Tissue Repair Market - Global Industry Analysis, Size, Share, Growth, Trends and Forecast, " PRNewswire. N.p., 25 Mar Web. 27 Oct Kirkendall, DT and Garrett, WE. Function and Biomechanics of Tendons. Scandinavian Journal of Medicine and Science in Sports. 2(1997): Web. 24 Oct Tendon. Encyclopaedia Britannica. Encyclopaedia Britannica, Inc. 2 Feb Web. 25 Oct Renstrom, Per A.F.H. and Lynch, Scott A. Ankle Ligament Injuries. Brazilian Journal of Sports Medicine. 4.3 (1998). Web. 27 Oct Erickson, Brandon J. et al. Trends in the Management of Achilles Tendon Ruptures in the United States Medicare Population, Orthopedic Journal of Sports Medicine. 2.9 (2014). Web. 27 Oct Schulze-Tanzil, Gundala et al. Decellularized Tendon Extracellular Matrix - A Valuable Approach for Tendon Reconstruction? Cells 1.4 (2012): PMC Web. 7 Nov Noyes, Frank R and Grood, Edward S. The Strength of the Anterior Cruciate Ligament in Humans and Rhesus Monkeys J of Bone and Joint Surgery. (1977): 58: ResearchGate Web. 1 Dec

20 Questions?

21 Tendon/Ligament Repair Utilizing Stromal Derived Factor Infused Alginate Coated Collagen Fibers Mario Rossi, Anne Tucker, Brian Ziola Dr. Yawen Li, Dr. Therese Bou-Akl, Dr. Tristan Maerz Objective: Design a biomimetic scaffold that attracts stem cells by the release of SDF-1 to replace damaged tendons/ligaments as a more effective method of tendon/ligament repair Approach: Electrospin collagen scaffolds and coat with alginate containing SDF-1 to attract MSCs to the scaffold Impact: A more effective method for tendon/ligament repair can improve the recovery time for patients which is highly important for athletes Progress and Results: An electrospun collagen fiber scaffold is being constructed with a coating of alginate that contains SDF-1. Various testing has been conducted to understand biocompatibility and ability to migrate stem cells 1. Electrospun collagen fiber scaffolds 2. Biocompatibility Study 3. SDF-1 Release Study 4. Mechanical Testing 5. Migration Study Electrospun collagen fibers After cross-linking Live-dead assay. Live cells in green and dead cells in red