A biomimetic honeycomb‐like scaffold prepared by flow‐focusing technology for cartilage regeneration

Abstract

A tissue engineering chondrocytes/scaffold construct provides a promise to cartilage regeneration. The architecture of a scaffold such as interconnections, porosities, and pore sizes influences the fates of seeding cells including gene expression, survival, migration, proliferation, and differentiation thus may determine the success of this approach. Scaffolds of highly ordered and uniform structures are desirable to control cellular behaviors. In this study, a newly designed microfluidic device based on flow-focusing geometry was developed to fabricate gelatin scaffolds of ordered pores. In comparison with random foam scaffolds made by the conventional freeze-dried method, honeycomb-like scaffolds exhibit higher swelling ratio, porosity, and comparable compressive strength. In addition, chondrocytes grown in the honeycomb-like scaffolds had good cell viability, survival rate, glycosaminoglycans production, and a better proliferation than ones in freeze-dried scaffolds. Real-time PCR analysis showed that the mRNA expressions of aggrecan and collagen type II were up-regulated when chondrocytes cultured in honeycomb-like scaffolds rather than cells cultured as monolayer fashion. Oppositely, chondrocytes expressed collagen type II as monolayer culture when seeded in freeze-dried scaffolds. Histologic examinations revealed that cells produced proteoglycan and distributed uniformly in honeycomb-like scaffolds. Immunostaining showed protein expression of S-100 and collagen type II but negative for collagen type I and X, which represents the chondrocytes maintained normal phenotype. In conclusion, a highly ordered and honeycomb-like scaffold shows superior performance in cartilage tissue engineering. Biotechnol. Bioeng. 2014;111: 2338-2348. © 2014 Wiley Periodicals, Inc.

Porous Polymeric Films from Microbubbles Generated Using a T-Junction Microfluidic Device

“…The ability to incorporate biomolecules (such as enzymes) into the porous films produced by multi-step methods, such as breath figure (8), can be greatly limited, since organic solvents (such as dichloromethane and carbon disulfide) are involved in the preparation process (9), which often damage the biomolecules. On the other hand, the more simplified (one-step) methods, such as the conventional casting of films (3) produce porous films with non-controlled pore sizes (10). As a result, we believe that there is a pressing need for developing new methods for the preparation of porous structures with controlled porosity, without involving harsh conditions, such as the involvement of organic solvents, heat treatments, etc.…”

Three‐dimensional spherical gelatin bubble‐based scaffold improves the myotube formation of H9c2 myoblasts

“…This bubble-based scaffold is fabricated using the flow-focusing method with a microfluidic device (Chung, Mishra, Wang, Lin, & Lin, 2009). Compared to those scaffolds prepared using the traditional freeze-dried method, the bubble-based scaffolds have a relatively higher swelling ratio, porosity, compressive strength, and expansion capacity (Wang et al, 2014(Wang et al, , 2016.…”

Intra‐articular Injection of platelet‐rich fibrin releasates in combination with bone marrow‐derived mesenchymal stem cells in the treatment of articular cartilage defects: An in vivo study in rabbits

“…The use of autologous MSCs to repair articular cartilage defects has been proposed . In fact, clinical approaches including Pridie's procedure, abrasion arthroplasty, and microfracture surgery all involve stimulating bone marrow to recruit MSCs from the subchondral bone for cartilage regeneration . Although still not used in daily practice, the use of intra‐articular injections of MSCs has been proposed to treat articular cartilage injuries caused by trauma and osteoarthritis (OA).…”

“…[8][9][10] In fact, clinical approaches including Pridie's procedure, abrasion arthroplasty, and microfracture surgery all involve stimulating bone marrow to recruit MSCs from the subchondral bone for cartilage regeneration. 11,12 Although still not used in daily practice, the use of intra-articular injections of MSCs has been proposed to treat articular cartilage injuries caused by trauma and osteoarthritis (OA). Phase I/II trials are currently being conducted, and preliminary results at 6 months postoperation showed that MSCs injection into the osteoarthritic knee improved function and pain without causing adverse events, and reduced cartilage defects by regeneration of hyaline-like articular cartilage.…”