Tissue Engineering. Part A

The arteriovenous loop (AVL) model allows the in vivo engineering of axially vascularized flaps, the so called AVL flaps. Although AVL flaps can be transplanted microsurgically to cover tissue defects, they lack an epithelial layer on the surface. Therefore, the objective of this study was to engineer axially vascularized AVL flaps with an accompanying epithelial layer for local defect reconstruction. In this study AVLs were established in 20 male Lewis rats. Minimally invasive injection of keratinocytes onto the surface of the AVL flaps was performed on postoperative day (POD) 21...

N/A.

Critical-sized mandibular bone defects, arising from e.g. resections after tumor surgeries, are currently treated with autogenous bone grafts. This treatment is considered very invasive and is associated with limitations such as morbidity, and graft resorption. Tissue engineering approaches propose to use 3D scaffolds that combine structural features, biomaterial properties, cells and biomolecules to create biomimetic constructs. However, mimicking the complex anatomy and composition of the mandible poses a challenge in scaffold design...

Extensively researched tissue engineering strategies involve incorporating cells into suitable biomaterials, offering promising alternatives to boost tissue repair. In this study, a hybrid scaffold Gel-DCM which integrated a photoreactive gelatin-hyaluronic acid hydrogel (Gel) with an oriented porous decellularized cartilage matrix (DCM) was designed for facilitating chondrogenic differentiation and cartilage repair. The Gel-DCM exhibited excellent biocompatibility in vitro, promoting favorable survival and growth of human adipose-derived stem cells (hADSCs) and articular chondrocytes (hACs)...

The extensive soft tissue defects resulting from trauma and tumors pose a prevalent challenge in clinical practice, characterized by a high incidence rate. Autologous tissue flap transplantation, considered the gold standard for treatment, is associated with various drawbacks, including the sacrifice of donor sources, postoperative complications, and limitations in surgical techniques, thereby impeding its widespread applicability. The emergence of tissue-engineered skin flaps, notably the acellular adipose flap (AAF), offers potential alternative solutions...

In recent years, there has been a significant expansion in the realm of processing microscopy images, thanks to the advent of machine learning techniques. These techniques offer diverse applications for image processing. Currently, numerous methods are employed for processing microscopy images in the field of biology, ranging from conventional machine learning algorithms to sophisticated deep learning artificial neural networks with millions of parameters. However, a comprehensive grasp of the intricacies of these methods usually necessitates proficiency in programming and advanced mathematics...

This study addresses a critical challenge in bioprinting for regenerative medicine, specifically the issue of hypoxia compromising cell viability in engineered tissues. To overcome this hurdle, a novel approach utilizing a microfluidic bioprinter is employed to create a two-layer structure resembling the human ovary. This structure incorporates a liposomal oxygen-releasing system to enhance cell viability. The bioprinting technique enables the simultaneous extrusion of two distinct bioinks, namely bioink A (comprising alginate 1% and 5mg/ml PEGylated fibrinogen in a 20:1 molar ratio) and bioink B (containing alginate 0...

Current treatment options for craniofacial volumetric muscle loss (VML) have disadvantages and cannot fully restore normal function. Bio-inspired semi-synthetic acrylated hyaluronic acid (AcHyA) hydrogel, which fills irregularly shaped defects, resembles an extracellular matrix, and induces a minimal inflammatory response, has shown promise in experimental studies of extremity VML. We therefore sought to evaluate the efficacy of AcHyA hydrogel in the treatment of craniofacial VML. For this, we used a novel model of masseter VML in the rat...

Negative pressure therapy (NPT) has been shown to facilitate wound healing and promote hair growth in a porcine model. However, there is a paucity of research on the impact of negative pressure on hair growth in murine models. Despite the ability of nude mice to develop hair follicles, the hair they produce is often flawed due to genetically induced keratin disorders, rendering them a pertinent animal model for assessing hair regeneration. Therefore, this study aims to investigate the effects of negative pressure on hair follicle growth in a nude mouse model...

Biomaterial scaffolds have been used successfully to promote the regenerative repair of small endometrial lesions in small rodents, providing partial restoration of gestational function. The use of rabbits in this study allowed us to investigate a larger endometrial tissue defect and myometrial-injury model. A gelatin/polycaprolactone (GT/PCL) gradient-layer biofilm was sutured at the defect to guide the reconstruction of the original tissue structure. 28 days post-implantation, the uterine cavity had been restored its original morphology; endometrial growth was accompanied by the formation of glands and blood vessels, and the fragmented myofibers of the uterine smooth muscle had begun to resemble the normal structure of the lagomorph uterine cavity, arranging in a circular luminal pattern and a longitudinal serosal pattern...

Amino acids are the essential building block for collagen and proteoglycan, which are the main constituents for cartilage extracellular matrix (ECM). Synthesis of ECM proteins require uptake of various essential/non-essential amino acids. Analyzing amino acids metabolism during chondrogenesis can help to relate tissue quality to amino acids metabolism under different conditions. In our study, we studied amino acids uptake/secretion using hMSC-based aggregate chondrogenesis in a serum-free induction medium with a defined chemical formulation...

Due to responses to reviewer comments, we are slightly above the word limit for the abstract. The revised version is included in the main manuscript text. Please let us know if this is an issue, and we can revise to try to get under the word limit. Thank you.

Juvenile idiopathic arthritis (JIA) is an inflammatory disease that can affect the temporomandibular joint (TMJ) and lower jaw growth. Better treatment options are needed, so this study investigated the effect of low intensity pulsed ultrasound (LIPUS) on TMJ arthritis. Seventy-two 3-week old male Wistar rats were in vivo micro-computed tomography (MicroCT) scanned and divided into 8 groups (n=9). These groups were Group 1 - TMJ arthritis and immediate LIPUS treatment (20 minutes/day, 4 weeks); Group 2 - immediate LIPUS treatment and no TMJ arthritis; Group 3 - TMJ arthritis and no LIPUS; Group 4 - no TMJ arthritis and no LIPUS; Group 5 - TMJ arthritis and LIPUS treatment with a delayed start by 4 weeks; Group 6 - delayed LIPUS and no TMJ arthritis; Group 7 - TMJ arthritis and no (delayed) LIPUS; and Group 8 - no TMJ arthritis and no (delayed) LIPUS...

In the realm of in situ cartilage engineering, the targeted delivery of both cells and hydrogel materials to the site of a defect serves to directly stimulate chondral repair. While the in situ application of stem cell-laden soft hydrogels to tissue defects holds great promise for cartilage regeneration, a significant challenge lies in overcoming the inherent limitation of these soft hydrogels, which must attain mechanical properties akin to the native tissue to withstand physiological loading. We therefore developed a system where a gelatin methacryloyl hydrogel laden with human adipose derived mesenchymal stem cells is combined with a secondary structure to provide bulk mechanical reinforcement...

Immune responses to biomedical implants, wound healing, and diseased tissues often involve collagen deposition by fibroblasts and other stromal cells. Dysregulated collagen deposition can lead to complications such as biomaterial fibrosis, cardiac fibrosis, desmoplasia, liver fibrosis, and pulmonary fibrosis, which can ultimately result in losses of organ function or failure of biomedical implants. Current in vitro methods to induce collagen deposition include growing the cells under macromolecular crowding conditions or on fibronectin-coated surfaces...

Adipose-derived stem cells (ADSC) are nowadays one of the most exploited cells in regenerative medicine. They are fast growing, capable of enhancing axonal elongation, support and locally stimulate Schwann cells (SC) and protect de-innervated muscles from atrophy after a peripheral nerve injury. With the aim of developing a bio-safe, clinically translatable cell-therapy, we assessed the effect of ADSC pre-expanded with human platelet lysate (hPL) in an in vivo rat model, delivering the cells into a 15 mm critical-size sciatic nerve defect embedded within a laminin-peptide-functionalised hydrogel (Biogelx-IKVAV) wrapped by a poly-"ℇ" -caprolactone (PCL) nerve conduit...

Osteoarthritis is a debilitating chronic joint disorder that affects millions of people worldwide. Since palliative and surgical treatments cannot completely regenerate hyaline cartilage within the articulating joint, osteochondral (OC) tissue engineering has been explored to heal these challenging defects. Using computational simulations and 3D printing, we aimed to build a strategy to fabricate OC scaffolds with enhanced biomechanics. First, computational simulations revealed that interfacial fibrils within a bilayer alter OC scaffold deformation patterns by redirecting load-induced stresses toward the top of the cartilage layer...

No abstract text is available yet for this article.

Cerebral cavitation is usual following acute brain injuries, such as stroke and traumatic brain injuries, as well as after tumor resection. Minimally-invasive implantation of an injectable scaffold in the cavity is a promising approach for potential regeneration of tissue loss. This study aimed to design an in situ gelling conductive hydrogel containing silk fibroin (SF), brain decellularized ECM (dECM), and carbon nanotubes (CNT) for potential use in brain tissue regeneration. 2% w/v SF hydrogels with different concentrations of dECM (0...

An essential aspect of cardiovascular in situ tissue engineering (TE) is to ensure balance between scaffold degradation and neo-tissue formation. We evaluated the degradation velocity and neo-tissue formation of three electrospun supramolecular bisurea-based biodegradable scaffolds that differ in their soft-block backbone compositions only. Scaffolds were implanted as interposition grafts in the abdominal aorta in rats, and evaluated at different time points (t = 1, 6, 12, 24 and 40 weeks) on function, tissue formation, strength and scaffold degradation...