Potential of Atlantic Codfish () Skin Collagen for Skincare Biomaterials.

Collagen is the major structural protein in extracellular matrix present in connective tissues, including skin, being considered a promising material for skin regeneration. Marine organisms have been attracting interest amongst the industry as an alternative collagen source. In the present work, Atlantic codfish skin collagen was analyzed, to evaluate its potential for skincare.

Laminin-2 immobilized on a 3D fibrous structure impacts cortical thymic epithelial cells behaviour and their interaction with thymocytes.

The tri-dimensionality of the thymic extracellular matrix (ECM) supports the crosstalk between thymocytes and thymic epithelial cells (TECs). The thymic ECM component laminin-2 is involved in the regulation of thymocytes and their interaction with cortical TECs (cTECs). Most in vitro studies use planar surfaces to study the interaction between ECM components and thymic cells.

Highly tailorable gellan gum nanoparticles as a platform for the development of T cell activator systems.

Background: T cell priming has been shown to be a powerful immunotherapeutic approach for cancer treatment in terms of efficacy and relatively weak side effects. Systems that optimize the stimulation of T cells to improve therapeutic efficacy are therefore in constant demand. A way to achieve this is through artificial antigen presenting cells that are complexes between vehicles and key molecules that target relevant T cell subpopulations, eliciting antigen-specific T cell priming.

Mechanomodulatory biomaterials prospects in scar prevention and treatment.

Scarring is a major clinical issue that affects a considerable number of patients. The associated problems go beyond the loss of skin functionality, as scars bring aesthetic, psychological, and social difficulties. Therefore, new strategies are required to improve the process of healing and minimize scar formation.

Correction: Strategies for the hypothermic preservation of cell sheets of human adipose stem cells.

[This corrects the article DOI: 10.1371/journal.pone.

Keratinocyte Growth Factor-Based Strategies for Wound Re-Epithelialization.

Wound re-epithelialization is a dynamic process that comprises the formation of new epithelium through an active signaling network between several growth factors (GFs) and various cell types. The main players are keratinocytes (KCs) that migrate from the wound edges over the wound bed to restore the epidermal barrier. One of the most important molecules involved in the re-epithelialization process is keratinocyte growth factor (KGF), a central player on promoting both migration and proliferation of KCs.

Rescuing key native traits in cultured dermal papilla cells for human hair regeneration.

Introduction: The dermal papilla (DP) represents the major regulatory entity within the hair follicle (HF), inducing hair formation and growth through reciprocal interactions with epithelial cells. However, human DP cells rapidly lose their hair inductive ability when cultured in an epithelium-deficient environment.

Objectives: To determine if the conditioned medium collected from interfollicular keratinocytes (KCs-CM) is capable of improving DP cell native properties and inductive phenotype.

Intracellular Autofluorescence as a New Biomarker for Cancer Stem Cells in Glioblastoma.

The identification of cancer stem cells (CSCs), which are implicated in tumor initiation, progression, therapy resistance, and relapse, is of great biological and clinical relevance. In glioblastoma (GBM), this is still a challenge, as no single marker is able to universally identify populations of GBM cancer stem cells (GSCs). Indeed, there is still controversy on whether biomarker-expressing cells fulfill the functional criteria of bona fide GSCs, despite being widely used.

Correction: vascularization of tissue engineered constructs by non-viral delivery of pro-angiogenic genes.

Correction for 'In vitro vascularization of tissue engineered constructs by non-viral delivery of pro-angiogenic genes' by Helena R. Moreira et al., Biomater.

In vitro vascularization of tissue engineered constructs by non-viral delivery of pro-angiogenic genes.

Vascularization is still one of the major challenges in tissue engineering. In the context of tissue regeneration, the formation of capillary-like structures is often triggered by the addition of growth factors which are associated with high cost, bolus release and short half-life. As an alternative to growth factors, we hypothesized that delivering genes-encoding angiogenic growth factors to cells in a scaffold microenvironment would lead to a controlled release of angiogenic proteins promoting vascularization, simultaneously offering structural support for new matrix deposition.

Interfollicular epidermal stem-like cells for the recreation of the hair follicle epithelial compartment.

Background: Hair follicle (HF) development and growth are dependent on epithelial-mesenchymal interactions (EMIs). Dermal papilla (DP) cells are recognized as the key inductive mesenchymal player, but the ideal source of receptive keratinocytes for human HF regeneration is yet to be defined. We herein investigated whether human interfollicular epidermal keratinocytes with stem-like features (EpSlKCs), characterized by a α6/CD71 expression, can replace human hair follicular keratinocytes (HHFKCs) for the recreation of the HF epithelium and respective EMIs.

Strategies for the hypothermic preservation of cell sheets of human adipose stem cells.

Cell Sheet (CS) Engineering is a regenerative medicine strategy proposed for the treatment of injured or diseased organs and tissues. In fact, several clinical trials are underway using CS-based methodologies. However, the clinical application of such cell-based methodologies poses several challenges related with the preservation of CS structure and function from the fabrication site to the bedside.

Interfollicular Epidermal Stem Cells: Boosting and Rescuing from Adult Skin.

Epidermal stem cells (EpSCs) isolation struggle remains, mainly due to the yet essential requirement of well-defined approaches and markers. The herein proposed methodology integrates an assemblage of strategies to accomplish the enrichment of the interfollicular EpSCs multipotent fraction and their subsequent separation from the remaining primary human keratinocytes (hKC) culture. Those include rapid adherence of freshly isolated hKC to collagen type IV through the β1-integrin ligand and Rho-associated protein kinase inhibitor (Rocki) Y-27632 administration to the cultures, followed by an immunomagnetic separation to obtain populations based in the combined CD49f/CD71 expression.

Gellan gum-hydroxyapatite composite spongy-like hydrogels for bone tissue engineering.

Osteoinductive biomaterials represent a promising approach to advance bone grafting. Despite promising, the combination of sustained biodegradability, mechanical strength, and biocompatibility in a unique biomaterial that can also support cell performance and bone formation in vivo is demanding. Herein, we developed gellan gum (GG)-hydroxyapatite (HAp) spongy-like hydrogels to mimic the organic (GG) and inorganic (HAp) phases of the bone.

Cell sheet engineering using the stromal vascular fraction of adipose tissue as a vascularization strategy.

Unlabelled: Current vascularization strategies for Tissue Engineering constructs, in particular cell sheet-based, are limited by time-consuming and expensive endothelial cell isolation and/or by the complexity of using extrinsic growth factors. Herein, we propose an alternative strategy using angiogenic cell sheets (CS) obtained from the stromal vascular fraction (SVF) of adipose tissue that can be incorporated into more complex constructs. Cells from the SVF were cultured in normoxic and hypoxic conditions for up to 8days in the absence of extrinsic growth factors.

Stem Cell-Containing Hyaluronic Acid-Based Spongy Hydrogels for Integrated Diabetic Wound Healing.

The detailed pathophysiology of diabetic foot ulcers is yet to be established and improved treatments are still required. We propose a strategy that directs inflammation, neovascularization, and neoinnervation of diabetic wounds. Aiming to potentiate a relevant secretome for nerve regeneration, stem cells were precultured in hyaluronic acid-based spongy hydrogels under neurogenic/standard media before transplantation into diabetic mice full-thickness wounds.

In vivo osteogenic differentiation of stem cells inside compartmentalized capsules loaded with co-cultured endothelial cells.

Unlabelled: Capsules coated with polyelectrolytes and co-encapsulating adipose stem (ASCs) and endothelial (ECs) cells with surface modified microparticles are developed. Microparticles and cells are freely dispersed in a liquified core, responsible to maximize the diffusion of essential molecules and allowing the geometrical freedom for the autonomous three-dimensional (3D) organization of cells. While the membrane wraps all the instructive cargo elements within a single structure, the microparticles provide a solid 3D substrate for the encapsulated cells.

Neovascularization Induced by the Hyaluronic Acid-Based Spongy-Like Hydrogels Degradation Products.

Neovascularization has been a major challenge in many tissue regeneration strategies. Hyaluronic acid (HA) of 3-25 disaccharides is known to be angiogenic due to its interaction with endothelial cell receptors. This effect has been explored with HA-based structures but a transitory response is observed due to HA burst biodegradation.

Growth Factor-Free Pre-vascularization of Cell Sheets for Tissue Engineering.

The therapeutic efficacy of tissue-engineered constructs is often compromised by inadequate inosculation and neo-vascularization. This problem is considered one of the biggest hurdles in the field and finding a solution is currently the focus of a great fraction of the research community. Many of the methodologies designed to address this issue propose the use of endothelial cells and angiogenic growth factors, or combinations of both, to accelerate neo-vascularization after transplantation.

Stem Cells in Skin Wound Healing: Are We There Yet?

Cutaneous wound healing is a serious problem worldwide that affects patients with various wound types, resulting from burns, traumatic injuries, and diabetes. Despite the wide range of clinically available skin substitutes and the different therapeutic alternatives, delayed healing and scarring are often observed. Stem cells have arisen as powerful tools to improve skin wound healing, due to features such as effective secretome, self-renewal, low immunogenicity, and differentiation capacity.

Semipermeable Capsules Wrapping a Multifunctional and Self-regulated Co-culture Microenvironment for Osteogenic Differentiation.

A new concept of semipermeable reservoirs containing co-cultures of cells and supporting microparticles is presented, inspired by the multi-phenotypic cellular environment of bone. Based on the deconstruction of the "stem cell niche", the developed capsules are designed to drive a self-regulated osteogenesis. PLLA microparticles functionalized with collagen I, and a co-culture of adipose stem (ASCs) and endothelial (ECs) cells are immobilized in spherical liquified capsules.

Gellan gum-hyaluronic acid spongy-like hydrogels and cells from adipose tissue synergize promoting neoskin vascularization.

Currently available substitutes for skin wound healing often result in the formation of nonfunctional neotissue. Thus, urgent care is still needed to promote an effective and complete regeneration. To meet this need, we proposed the assembling of a construct that takes advantage of cell-adhesive gellan gum-hyaluronic acid (GG-HA) spongy-like hydrogels and a powerful cell-machinery obtained from adipose tissue, human adipose stem cells (hASCs), and microvascular endothelial cells (hAMECs).

Engineering cell-adhesive gellan gum spongy-like hydrogels for regenerative medicine purposes.

The similarity between the extracellular matrix of soft tissue and hydrogels, characterized by high-water-content viscoelastic polymeric networks, has been sustaining the advancement of hydrogels for tissue engineering and regenerative medicine (TERM) purposes. Current research on hydrogels has focused on introducing cell-adhesive peptides to promote cell adhesion and spreading, a critical applicability limitation. Here we report the development of gellan gum (GG) spongy-like hydrogels with ameliorated mechanical performance and flexibility in relation to hydrogels, using a simple and cost-effective method.