Ronaldo J F C Do Amaral

Federal University of Rio de Janeiro | UFRJ · Institute of Biomedical Sciences

Overexpression of human epidermal growth factor receptor-2 (HER-2) occurs in 20% of all breast cancer subtypes, especially those that present the worst prognostic outcome through a very invasive and aggressive tumour. HCC-1954 (HER-2+) is a highly invasive, metastatic cell line, whereas MCF-7 is mildly aggressive and non-invasive. We investigated m...

Diabetic foot ulcers (DFUs) are chronic wounds sustained by pathological fibroblasts and aberrant extracellular matrix (ECM). Porous collagen‐based scaffolds (CS) have shown clinical promise for treating DFUs but may benefit from functional enhancements. Our previous work showed fibroblasts differentiated from induced pluripotent stem cells are an...

Introduction and hypothesis: The use of polypropylene (PP) mesh for stress urinary incontinence (SUI) surgery has declined because of safety concerns. The aim of this study is to evaluate a biodegradable polycaprolactone (PCL) mesh and a PCL composite mesh tissue engineered with human uterine fibroblasts (HUFs) for SUI surgery by comparing mechani...

Despite the high success rate of autologous grafts in tympanic membrane repair, clinical alternatives are required for the closure of unresponsive chronic perforations that can lead to recurring infection and hearing loss. Tissue engineering and regenerative medicine approaches have emerged as another strategy to repair the eardrum, in addition to...

Successful therapeutic strategies for wound healing rely on proper vascularization while inhibiting fibrosis. However, scaffolds designed for skin tissue engineering generally lack the biochemical cues that can enhance their vascularization without inducing fibrosis. Therefore, the objective of this work is to incorporate platelet-rich plasma (PRP)...

Impaired skin wound healing due to severe injury often leads to dysfunctional scar tissue formation as a result of excessive and persistent myofibroblast activation, characterised by the increased expression of alpha-smooth muscle actin (alphaSMA) and extracellular matrix (ECM) proteins. Yet, despite extensive research on impaired wound healing and...

Poly(globalide) (PGl), an aliphatic polyester derived from unsaturated macrocylic lactone, can be cross‐linked during electrospinning and drug‐loaded for regenerative medicine applications. However, it lacks intrinsic recognition sites for cell adhesion and proliferation. In order to improve their cell adhesiveness, and therefore their therapeutic...

Commercial cell-based skin regenerative products are highly expensive, carry the risk of rejection and require a long cell culture period to manufacture. This work describes the synthesis of bilayer films from poly(globalide) (PGl) and regenerated cellulose nanofibers (rCNFs) and their use as a cell-free scaffold to support keratinocyte attachment...

Correction for ‘Development of wound healing scaffolds with precisely-triggered sequential release of therapeutic nanoparticles’ by Tauseef Ahmad et al. , Biomater. Sci. , 2020, DOI: 10.1039/d0bm01277g.

Natural bioactive cue profiles are generally transient with cues switching on/off to coordinate successful outcomes. Dysregulation of these sequences typically leads to disease. Successful wound healing, for example, should progress sequentially through hemostasis, inflammation, granulation tissue formation, and maturation. Chronic wounds, such as...

Extracellular matrix (ECM)‐derived scaffolds show promise in a variety of tissue engineering applications. In article number 2000307, Cathal J. Kearney and co‐workers exploit ECM grown by cells differentiated from induced pluripotent stem cells for scaffold fabrication and examine their potential for diabetic wound healing. This ECM has previously...

Diabetic foot ulcers (DFUs) are chronic wounds, with 20% of cases resulting in amputation, despite intervention. A recently approved tissue engineering product—a cell‐free collagen‐glycosaminoglycan (GAG) scaffold—demonstrates 50% success, motivating its functionalization with extracellular matrix (ECM). Induced pluripotent stem cell (iPSC) technol...

Symptomatic stress urinary incontinence (SUI) and pelvic organ prolapse (POP) refractory to conservative management with pelvic floor muscle training or vaginal pessaries, may warrant surgical intervention with different forms of biologic or synthetic material. However, in recent years several global regulatory agencies have issued health warnings...

Phosphoester containing polymers are promising materials in biomedical applications due to their biocompatibility and biodegradability. Utilising thiol-ene chemistry, the synthesis of two novel structural polymer motives combining polyesters and phophoester groups was explored. The first polymer was obtained by coupling ene-functional poly(thioethe...

Porous collagen-glycosaminoglycan (collagen-GAG) scaffolds have shown promising clinical results for wound healing; however, these scaffolds do not replace the dermal and epidermal layer simultaneously and rely on local endogenous signaling to direct healing. Functionalizing collagen-GAG scaffolds with signaling factors, and/or additional matrix mo...

Purpose To compare the clinical and laboratory outcomes of intra-articular injections of culture-expanded bone-derived mesenchymal stem cells (MSCs) with or without platelet-rich plasma (PRP) to intra-articular corticosteroid injections for the treatment of knee osteoarthritis (OA). Methods Forty-seven patients with radiographic and symptomatic kn...

Collagen‐glycosaminoglycan (CG) scaffolds have been widely developed for a range of regenerative medicine applications. To enhance their efficacy, CG scaffolds have previously been pre‐vascularised in vitro using human endothelial cells and mesenchymal stromal cells (hMSC); however, at later time‐points, a regression of vascularisation is observed....

There are several pathologies associated with the peritoneum, such as mesothelioma and peritonitis. Moreover, the peritoneum is widely used in ultrafiltration procedures, i.e., peritoneal dialysis, presenting advantages over hemodialysis. On the other hand, ultrafiltration failure may lead to dialysis-induced fibrosis and hypervolemia. Therefore, t...

The ideal cell type to be used for cartilage therapy should possess a proven chondrogenic capacity, not cause donor-site morbidity, and should be readily expandable in culture without losing their phenotype. There are several cell sources being investigated to promote cartilage regeneration: mature articular chondrocytes, chondrocyte progenitors, a...

There are promising results in the use of platelet-rich plasma (PRP) for musculoskeletal tissue repair. However, the variability in the methodology for its obtaining may cause different and opposing findings in the literature. Particularly, the choice of the anticoagulant is the first definition to be made. In this work, blood was collected with so...

Platelets are especially well known for their thrombotic role. However, besides their role on stopping bleeding, platelets contribute for several mechanisms and steps in wound healing and tissue repair, such as inflammation, angiogenesis, cells proliferation, and differentiation. The potential of platelets to be used therapeutically to assist in wo...

Platelet-rich plasma has been used to treat articular cartilage defects, with the expectations of anabolic and anti-inflammatory effects. However, its role on cellular chondrogenic or fibrogenic commitment is still a controversy. Herein, the role of platelet-rich plasma releasate, the product obtained following platelet-rich plasma activation, on c...

The peritoneum is a thin membrane that covers most of the abdominal organs, composed of a monolayer of mesothelial cells and subjacent submesothelial loose connective tissue. Cells from the peritoneal wall are correlated with peritoneal fibrosis and epithelial-to-mesenchymal transition. However, the distinct involvement of mesothelial or submesothe...

The objective of our study was to investigate chondrogenesis potential of human adipose-derived mesenchymal stromal cells (MSCs), using as a positive control a human source of cartilage-derived progenitor cells (PCs). This source of PCs was recently described by our group and dwells on the surface of nasoseptal cartilage. Histological analysis usin...

Introduction Platelet-rich plasma (PRP) is nowadays widely applied in different clinical scenarios, such as orthopedics, ophthalmology and healing therapies, as a growth factor pool for improving tissue regeneration. Studies into its clinical efficiency are not conclusive and one of the main reasons for this is that different PRP preparations are u...

In cartilaginous tissues, perichondrium cambium layer may be the source of new cartilage. Human nasal septal perichondrium is considered to be a homogeneous structure in which some authors do not recognize the perichondrium internal zone or the cambium layer as a layer distinct from adjacent cartilage surface. In the present study, we isolated a ch...

Since initial methods were developed for isolating cells from adipose tissue, little has been done to improve mesenchymal stromal cell (MSC) yield. The aim of the present study was to isolate a population of MSC from lipoaspirate samples without tissue digestion and to assess the possibility of cryopreserving the freshly isolated cells. A populatio...

Silks are naturally occurring polymers and fibroin, its filament core protein, has been shown to support stem cell differentiation in vitro, and promote tissue repair in vivo. The aim of this study is to develop a biomaterial based on silk-fibroin fibers that can be associated with mesenchymal progenitor cells from human perichondrium in vitro, in...