Soft Tissue Repair and Biomaterials

Soft Tissue Repair & Biomaterials

Presenter Details

  • Kritika Srinivasan Rajsri, B.D.S, M.S, Ph.D.
    Department of Molecular Pathobiology, NYUCD
    Email: ks3144@nyu.edu

Outline

  1. Skin Repair

  2. Oral Soft Tissue Repair

    • Periodontal tissue

    • Pulp-Dentine

    • Oral Mucosa

  3. Tendon and Ligament Repair

  4. Fascia & Muscle Repair

    • Hernia Repair — 3D scaffolds for soft tissue repair

  5. Nerve Repair

1. Skin

The Simplest Soft Tissue Repair

  • Techniques: Sutures, Staples, Adhesives
    Soft tissue repair - Skin

  • Layers of the Skin: Illustrated with references to Madhero88 and M. Komorniczak.

  • Types of Wound Healing: Referenced in Illustrated Surgery, includes a comparison to Regeneration vs. Repair.

    • Regeneration (epithelialization): Process returning the site of injury to its original state, observed in minor lacerations.

    • Reparation (tissue repair): Process generating a scar or less functional tissue differing in form and/ or composition from the original tissue, not restoring complete functionality.

Types of Skin Reparation

  1. Clean incised wound/surgical wound: Closed by re-epithelialization.

  2. Contaminated wound or tissue loss (e.g., lacerations, burns, and ulcers): Treated by delayed closure, requiring surgical intervention like debridement prior to closure using grafts or flaps.

2. Oral Soft Tissue Repair

Natural Biomaterials

  • Mucograft®: A sterile, non-cross-linked collagen bi-layer matrix derived from porcine type I and III collagen.

    • Function: As a barrier preventing cell adhesion and trauma, while the porous side encourages soft tissue cell invasion and blood clot stabilization, promoting tissue growth.

    • Uses: Socket preservation, augmenting keratinized gingival tissue around teeth or implants, recession coverage, alternatives to autogenous grafts.

  • Bio-Gide®: A resorbable bilayer collagen membrane made from porcine collagen.

    • Function: Acts as a barrier to prevent soft tissue infiltration in bone defects, promotes new bone and soft tissue growth.

    • Uses: Guided tissue regeneration, extraction socket management.

  • Chitosan: A natural biomaterial derived from chitin, with potential uses in tissue engineering.

  • Mucoderm®: A purified, acellular, 3-dimensional collagen matrix that fosters rapid integration of soft tissues by supporting cellular adhesion and proliferation.

    • Uses: Gingival recessions, peri-implant soft tissue augmentation.

  • AlloDerm: An acellular dermal matrix made from human skin, serves as a biological scaffold for tissue regeneration, minimizing immune rejection risk.

Synthetic Polymers/Composite

  • Hydrogel Scaffold with Chitin: Constructed from multiple components to achieve regeneration and closure of periodontal defects, demonstrating efficacy in in-vivo studies.

Bioprinting

  • Innovative Bioprinting Techniques: Used for constructing scaffolds and modules for enhanced periodontal tissue regeneration, involving cell-laden bioinks and CAD/CAM technology.

3. Tendon and Ligament Repair

Tendon & Ligament Tissues

  • Function of Tendons: Attach muscles to bones, transmitting forces to create joint movement, capable of resisting tensile and compressive forces.

  • Function of Ligaments: Connect bones for joint stability, guiding joint motion and preventing dislocation.

Histopathology

  • Structure comparison shows that both tendons and ligaments possess highly aligned collagen fibres, conferring excellent resistance to mechanical loads. Tendons and ligaments differ slightly in resident cell types and collagen structure.

Repair Challenges

  • Adhesion Prevention: Tendons heal from local cell sources and can form adhesions, complicating recovery. Research focuses on minimizing fibrosis using various biomaterials.

4. Fascia & Muscle Repair

Hernia Repair

  • Biomaterials Used in Hernia Repair:

    • Non-absorbable materials: E.g., polypropylene (PP), polyethylene terephthalate (PET).

    • Absorbable materials: E.g., poly (glycolic) acid (PGA), polylactide.

Mesh Prostheses

  • Coated meshes: Functionalized surfaces to improve tissue integration, reduce foreign body response, and decrease complications from hernioplasty.

5. Nerve Repair

Biomaterials for Nerve Repair

  • NeuraGen® Nerve Guide: A biocompatible collagen tube aiding nerve regeneration by providing a conduit for axonal growth.

Nerve Conduits and Wraps

  • Structures like NeuroMatrix and NeuroMend allowing nutrient diffusion while protecting nerves from scar formation.

  • RevolNerv®: A porcine collagen tube promoting nerve healing by directing growth.

Summary of Key Biomathematics

  1. Structural Support & Functionality: Biomaterials provide scaffolding, guide cellular growth and remodeling, and can deliver therapeutic agents.

  2. Types of Biomaterials: Include natural (collagen, gelatin) and synthetic (PLA, PGA) polymers used as hydrogels, films, or 3D-printed scaffolds.

  3. Essential Material Properties: Biocompatibility, appropriate mechanical properties, controlled biodegradability requisite for effective integration and healing.