Prediction of the "in vivo" mechanical behavior of biointegrable acrylic macroporous scaffolds.

This study examines a biocompatible scaffold series of random copolymer networks P(EA-HEA) made of Ethyl Acrylate, EA, and 2-Hydroxyl Ethyl Acrylate, HEA. The P(EA-HEA) scaffolds have been synthesized with varying crosslinking density and filled with a Poly(Vinyl Alcohol), PVA, to mimic the growing cartilaginous tissue during tissue repair. In cartilage regeneration the scaffold needs to have sufficient mechanical properties to sustain the compression in the joint and, at the same time, transmit mechanical signals to the cells for chondrogenic differentiation.

Implantation of a polycaprolactone scaffold with subchondral bone anchoring ameliorates nodules formation and other tissue alterations.

Purpose: Articular cartilage has limited repair capacity. Two different implant devices for articular cartilage regeneration were tested in vivo in a sheep model to evaluate the effect of subchondral bone anchoring for tissue repair.

Methods: The implants were placed with press-fit technique in a cartilage defect after microfracture surgery in the femoral condyle of the knee joint of the sheep and histologic and mechanical evaluation was done 4.

Relationship between micro-porosity, water permeability and mechanical behavior in scaffolds for cartilage engineering.

In tissue engineering the design and optimization of biodegradable polymeric scaffolds with a 3D-structure is an important field. The porous scaffold provide the cells with an adequate biomechanical environment that allows mechanotransduction signals for cell differentiation and the scaffolds also protect the cells from initial compressive loading. The scaffold have interconnected macro-pores that host the cells and newly formed tissue, while the pore walls should be micro-porous to transport nutrients and waste products.

An experimental fatigue study of a porous scaffold for the regeneration of articular cartilage.

The aim of this experimental study is to predict the long-term mechanical behavior of a porous scaffold implanted in a cartilage defect for tissue engineering purpose. Fatigue studies were performed by up to 100,000 unconfined compression cycles in a polycaprolactone (PCL) scaffold with highly interconnected pores architecture. The scaffold compliance, stress-strain response and hysteresis energy have been measured after different number of fatigue cycles, while the morphology has been observed by scanning electron microscopy at the same fatigue times.

In vitro mechanical fatigue behavior of poly-ɛ-caprolactone macroporous scaffolds for cartilage tissue engineering: Influence of pore filling by a poly(vinyl alcohol) gel.

Polymeric scaffolds used in regenerative therapies are implanted in the damaged tissue and submitted to repeated loading cycles. In the case of articular cartilage engineering, an implanted scaffold is typically subjected to long-term dynamic compression. The evolution of the mechanical properties of the scaffold during bioresorption has been deeply studied in the past, but the possibility of failure due to mechanical fatigue has not been properly addressed.

An "in vitro" experimental model to predict the mechanical behavior of macroporous scaffolds implanted in articular cartilage.

A model is proposed to assess mechanical behavior of tissue engineering scaffolds and predict their performance "in vivo" during tissue regeneration. To simulate the growth of tissue inside the pores of the scaffold, the scaffold is swollen with a Poly (Vinyl alcohol) solution and subjected to repeated freezing and thawing cycles. In this way the Poly (Vinyl alcohol) becomes a gel whose stiffness increases with the number of freezing and thawing cycles.

Grid polymeric scaffolds with polypeptide gel filling as patches for infarcted tissue regeneration.

Scaffolds of poly(ethyl acrylate) (PEA) with interconnected cylindrical orthogonal pores filled with a self-assembling peptide (SAP) gel are here proposed as patches for infarcted tissue regeneration. These combined systems aim to support cell therapy and meet further requirements posed by the application: the three-dimensional architecture of the elastomeric scaffold is expected to lodge the cells of interest in the damaged zone avoiding their death or migration, and at the same time conduct cell behavior and give mechanical support if necessary; the ECM-like polypeptide gel provides a cell-friendly aqueous microenvironment, facilitates diffusion of nutrients and cell wastes and is expected to improve the distribution and viability of the seeded cells within the pores and stimulate angiogenesis.

Fatigue prediction in fibrin poly-ε-caprolactone macroporous scaffolds.

Tissue engineering applications rely on scaffolds that during its service life, either for in-vivo or in vitro applications, are under loading. The variation of the mechanical condition of the scaffold is strongly relevant for cell culture and has scarcely been addressed. The fatigue life cycle of poly-ε-caprolactone, PCL, scaffolds with and without fibrin as filler of the pore structure were characterized both dry and immersed in liquid water.

Combining self-assembling peptide gels with three-dimensional elastomer scaffolds.

Some of the problems raised by the combination of porous scaffolds and self-assembling peptide (SAP) gels as constructs for tissue engineering applications are addressed for the first time. Scaffolds of poly(ethyl acrylate) and the SAP gel RAD16-I were employed. The in situ gelation of the SAP gel inside the pores of the scaffolds was studied.