Comparison of Two Percutaneous Atrial Septal Defect Occluders for Device Healing and Nickel Release in a Chronic Porcine Model.

Aims: To investigate the healing process and nickel release of the Hyperion occluder (Comed BV, Netherlands), as compared to the Amplatzer septal occluder (ASO) (St. Jude Medical Inc., St.

In situ prevascularization designed by laser-assisted bioprinting: effect on bone regeneration.

Vascularization plays a crucial role in bone formation and regeneration process. Development of a functional vasculature to improve survival and integration of tissue-engineered bone substitutes remains a major challenge. Biofabrication technologies, such as bioprinting, have been introduced as promising alternatives to overcome issues related to lack of prevascularization and poor organization of vascular networks within the bone substitutes.

Cell and tissue responses at the interface with a chitosan hydrogel intended for vascular applications: in vitro and in vivo exploration.

Aims: The need for small caliber vessels to treat cardiovascular diseases has grown. However, synthetic polymers perform poorly in small-diameter applications. Chitosan hydrogels can provide a novel biological scaffold for vascular engineering.

Colorectal wall regeneration resulting from the association of chitosan hydrogel and stromal vascular fraction from adipose tissue.

Chitosan hydrogel and adipose derived stem cells (ADCS) have been reported as the optimal partnership for colorectal tissue engineering. In that field, the aim of the current experiment was to assess the interest of seeding ADSC on chitosan hydrogel patches in an in vivo comparative study and on a tube intended replace a colonic segment in an in vivo feasibility study. In the comparative study, a 2 × 3 cm colonic wall defect was performed in 20 swine and repaired by suturing a chitosan hydrogel patch: acellular matrix (group A, n = 10) versus matrix seeded with autologous stromal vascular fraction (SVF) (group B, n = 10).

In situ printing of mesenchymal stromal cells, by laser-assisted bioprinting, for in vivo bone regeneration applications.

Bioprinting has emerged as a novel technological approach with the potential to address unsolved questions in the field of tissue engineering. We have recently shown that Laser Assisted Bioprinting (LAB), due to its unprecedented cell printing resolution and precision, is an attractive tool for the in situ printing of a bone substitute. Here, we show that LAB can be used for the in situ printing of mesenchymal stromal cells, associated with collagen and nano-hydroxyapatite, in order to favor bone regeneration, in a calvaria defect model in mice.

Unexpected Internalization of a Pulmonary Artery Band in a Porcine Model of Tetralogy of Fallot.

Background: We report our experience of an unexpected complication of internalization of a pulmonary artery (PA) band in the vascular lumen, which occurred in a chronic porcine model of repaired tetralogy of Fallot (TOF).

Methods: Twelve piglets were divided into 3 groups: (1) TOF model animals (PA band plus pulmonary valvotomy, n = 4), (2) pulmonary insufficiency (PI) animals (pulmonary valvotomy, n = 4), and (3) control animals (n = 4). A nonabsorbable, coated braided polyester tape was used to perform the main pulmonary artery banding.

Colorectal tissue engineering: A comparative study between porcine small intestinal submucosa (SIS) and chitosan hydrogel patches.

Objective: Tissue engineering may provide new operative tools for colorectal surgery in elective indications. The aim of this study was to define a suitable bioscaffold for colorectal tissue engineering.

Methods: We compared 2 bioscaffolds with in vitro and in vivo experiments: porcine small intestinal submucosa (SIS) versus chitosan hydrogel matrix.

Bioresorption mechanisms of chitosan physical hydrogels: a scanning electron microscopy study.

Tissue-engineered biodegradable medical devices are widely studied and systems must present suitable balance between versatility and elaboration simplicity. In this work, we aim at illustrating that such equilibrium can be found by processing chitosan physical hydrogels without external cross-linker. Chitosan concentration, degree of acetylation, solvent composition, and neutralization route were modulated in order to obtain hydrogels exhibiting different physico-chemical properties.

Physicochemical modulation of chitosan-based hydrogels induces different biological responses: interest for tissue engineering.

Polysaccharide-based hydrogels are remarkable materials for the development of tissue engineering strategies as they meet several critical requirements for such applications and they may partly mimic the extracellular matrix. Chitosan is widely envisioned as hydrogel in biomedical fields for its bioresorbability, biocompatibility, and fungistatic and bacteriostatic properties. In this study, we report that the modulation of the polymer concentration, the degree of acetylation, the gelation processes [or neutralization routes (NR)] in the preparation of different chitosan-based hydrogels lead to substantially and significantly different biological responses.

Assessment of biphasic calcium phosphate to repair nasal septum defects in sheep.

Background: Saddle nose and septal perforations are among the most surgically challenging situations in nasal reconstruction. They require a significant volume of autologous graft and a complex surgical procedure. The aim of this study was to evaluate the biocompatibility of the biphasic calcium phosphate implant in the nasal septum and its ability to replace septal skeleton with unilateral or bilateral exposure.