Biomimetic poly(lactide) based fibrous scaffolds for ligament tissue engineering

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Orthopedic Research

Background:

• The anterior cruciate ligament (ACL) plays a crucial role in knee stability.
• Native ACL collagen fibers exhibit a unique crimp structure and mechanical properties.
• Current tissue engineering scaffolds often lack the micro-architectural features of native tissues.

Purpose of the Study:

• To fabricate a fibrous scaffold that replicates the micro-structural architecture and mechanical properties of native ACL collagen fibers.
• To evaluate the biocompatibility and degradation profile of L-lactide based polymers for scaffold fabrication.
• To assess the potential of the fabricated scaffold for promoting extracellular matrix deposition by seeded cells.

Main Methods:

• Electrospinning of L-lactide based polymers, including poly(L-lactide-co-D,L-lactide) (PLDLA).
• Collection of electrospun fibers under tension on a rotating mandrel to induce alignment.
• Post-fabrication treatment in a heated aqueous environment to create a crimp-like pattern.
• In vitro hydrolytic degradation studies over 6 months.
• Seeding of bovine fibroblasts onto the scaffolds and assessment of cell attachment, proliferation, and extracellular matrix (ECM) deposition.

Main Results:

• Fibrous scaffolds with a crimp-like pattern, mimicking native ACL collagen, were successfully fabricated.
• PLDLA scaffolds demonstrated the highest modulus and superior resilience to in vitro hydrolytic degradation compared to other L-lactide based polymers.
• Bovine fibroblasts seeded on PLDLA scaffolds exhibited robust attachment, proliferation, and significant deposition of ECM molecules.
• The deposited ECM showed bundle formation resembling native ACL fascicles, indicating successful recapitulation of the microenvironment.

Conclusions:

• The electrospinning technique combined with post-fabrication treatment can effectively replicate the micro-structural and mechanical characteristics of ACL collagen fibers.
• PLDLA is a promising biomaterial for developing tissue engineering scaffolds due to its mechanical strength and degradation resistance.
• Replicating the native geometric microenvironment is critical for developing effective tissue engineering scaffolds that promote functional tissue regeneration.