Vincenzo Vindigni

High glucose induces adipogenic differentiation of muscle-derived stem cells.

Regeneration of mesenchymal tissues depends on a resident stem cell population, that in most cases remains elusive in terms of cellular identity and differentiation signals. We here show that primary cell cultures derived from adipose tissue or skeletal muscle differentiate into adipocytes when cultured in high glucose. High glucose induces ROS production and PKCβ activation. These two events appear crucial steps in this differentiation process that can be directly induced by oxidizing agents and inhibited by PKCβ siRNA silencing. The differentiated adipocytes, when implanted in vivo, form viable and vascularized adipose tissue. Overall, the data highlight a previously uncharacterized differentiation route triggered by high glucose that drives not only resident stem cells of the adipose tissue but also uncommitted precursors present in muscle cells to form adipose depots. This process may represent a feed-forward cycle between the regional increase in adiposity and insulin resistance that plays a key role in the pathogenesis of diabetes mellitus.

Active Silver Nanoparticles for Wound Healing

In this preliminary study, the silver nanoparticle (Ag NP)-based dressing, Acticoat™ Flex 3, has been applied to a 3D fibroblast cell culture in vitro and to a real partial thickness burn patient. The in vitro results show that Ag NPs greatly reduce mitochondrial activity, while cellular staining techniques show that nuclear integrity is maintained, with no signs of cell death. For the first time, transmission electron microscopy (TEM) and inductively coupled plasma mass spectrometry (ICP-MS) analyses were carried out on skin biopsies taken from a single patient during treatment. The results show that Ag NPs are released as aggregates and are localized in the cytoplasm of fibroblasts. No signs of cell death were observed, and the nanoparticles had different distributions within the cells of the upper and lower dermis. Depth profiles of the Ag concentrations were determined along the skin biopsies. In the healed sample, most of the silver remained in the surface layers, whereas in the unhealed sample, the silver penetrated more deeply. The Ag concentrations in the cell cultures were also determined. Clinical observations and experimental data collected here are consistent with previously published articles and support the safety of Ag NP-based dressing in wound treatment.

Necrotizing fasciitis: classification, diagnosis, and management.

Necrotizing fasciitis (NF), a life-threatening rare infection of the soft tissues, is a medical and surgical emergency. It is characterized by subtle, rapid onset of spreading inflammation and necrosis starting from the fascia, muscles, and subcutaneous fat, with subsequent necrosis of the overlying skin. Once suspected, immediate and extensive radical debridement of necrotic tissues is mandatory. Appropriate antibiotics and intensive general support avoid massive systemic diffusion of the infective process and are the key for successful treatment. However, early diagnosis is missed or delayed in 85% to 100% of cases in large published series: because of the lack of specific clinical features in the initial stage of the disease, it is often underestimated or confused with cellulitis or abscess. Mortality rates are still high and have shown no tendency to decrease in the last 100 years. Unfortunately, the prevalence of the disease is such that physicians rarely become sufficiently confident with NF to be able to proceed with rapid diagnosis and management. This review covers the literature published in MEDLINE in the period 1970 to December 31, 2010. Particular attention is given to the clinical and laboratory elements to be considered for diagnosis. A wide variety of diagnostic tools have been described to facilitate and hasten the diagnosis of NF, but the most important tool for early diagnosis still remains a high index of clinical suspicion.

Silver Nanoparticles and Mitochondrial Interaction

Nanotechnology has gone through a period of rapid growth, thus leading to the constant increase in the application of engineered nanomaterials in daily life. Several different types of nanoparticles have been engineered to be employed in a wide array of applications due to their high surface to volume ratio that leads to unique physical and chemical properties. So far, silver nanoparticles (AgNps) have been used in many more different medical devices than any other nanomaterial, mainly due to their antimicrobial properties. Despite the promising advantages posed by using AgNps in medical applications, the possible health effects associated with the inevitable human exposure to AgNps have raised concerns as to their use since a clear understanding of their specific interaction with biological systems has not been attained yet. In light of such consideration, aim of the present work is the morphological analysis of the intracellular behavior of AgNps with a diameter of 10 nm, with a special attention to their interaction with mitochondria.

Hyaluronan benzyl ester as a scaffold for tissue engineering.

Tissue engineering is a multidisciplinary field focused on in vitro reconstruction of mammalian tissues. In order to allow a similar three-dimensional organization of in vitro cultured cells, biocompatible scaffolds are needed. This need has provided immense momentum for research on “smart scaffolds” for use in cell culture. One of the most promising materials for tissue engineering and regenerative medicine is a hyaluronan derivative: a benzyl ester of hyaluronan (HYAFF®). HYAFF® can be processed to obtain several types of devices such as tubes, membranes, non-woven fabrics, gauzes, and sponges. All these scaffolds are highly biocompatible. In the human body they do not elicit any adverse reactions and are resorbed by the host tissues. Human hepatocytes, dermal fibroblasts and keratinocytes, chondrocytes, Schwann cells, bone marrow derived mesenchymal stem cells and adipose tissue derived mesenchymal stem cells have been successfully cultured in these meshes. The same scaffolds, in tube meshes, has been applied for vascular tissue engineering that has emerged as a promising technology for the design of an ideal, responsive, living conduit with properties similar to that of native tissue.

Stable muscle atrophy in long-term paraplegics with complete upper motor neuron lesion from 3-to 20-year SCI

Study design:Unrandomized trial.Objectives:To investigate the structural and functional relationships and the progression of muscle atrophy up to 20 years of spastic paraplegia.Setting:Clinical follow-up in Vienna, Austria; muscle biopsies analyzed by light microscopy in Padova and by electron microscopy (EM) in Chieti, Italy.Methods:Force was measured as knee extension torque; trophism by computer tomography scan; tissue composition and fiber morphology by histopathology and EM.Results:In the long-term group of patients (17.0±2.6 years), force and size of thigh muscles were only slightly different from those of mid-term subjects (2.2±0.5 years). Histology and ultrastructure confirm that the difference in average size of muscle fibers between long-term and mid-term paralyzed leg muscles is actually very small. In addition, muscle fibers maintain the striated appearance characteristic of normal skeletal fibers even after 14–20 years of paralysis. Ultrastructural alterations of the activating and metabolic machineries, and the presence of fibers with lower motor neuron denervation features, may explain the low-force output and the reduced endurance of paretic muscles.Conclusion:The stable muscle atrophy that characterizes long-lasting spastic paraplegia suggests that there are no upper-time limits to begin a training program based on functional electrical stimulation.

In vitro reconstruction of an endothelialized skin substitute provided with a microcapillary network using biopolymer scaffolds

Successful in vitro reconstruction of skin requires the inclusion of several cell types that give rise in coculture to the specific elements present in native skin, and the appropriate scaffolding structure to house and support these cells. In addition to the two main structural components, epidermis and dermis, one critical apparatus of the skin is a capillary network that guarantees adequate perfusion of nutrients and oxygen. The aim of the present study was to develop an in vitro coculture system that assumed the human dermal‐epidermal architecture and included a microcapillary network in a three‐dimensional biomaterial that guaranteed ease of handling in a clinical setting. Endothelialized skin (ES) was prepared by coculturing three human cell types: keratinocytes, fibroblasts, and endothelial cells, obtained from human full‐thickness skin samples, in scaffolds produced from modified hyaluronic acid. Results were evaluated by histological and immunohistochemical analyses at different time points. In vitro, engineered skin obtained with this composite culture developed into a well‐differentiated upper layer of stratified keratinocytes lining a dermal‐like structure, in which fibroblasts, extracellular matrix and a microvascular network were present. Furthermore, the biodegradable fabric produced from hyaluronic acid and used as the scaffolding support for this in vitro constructed skin graft greatly facilitated handling in the perioperative period.

Psychopathologic Aspects of Body Dysmorphic Disorder: A Literature Review

Body dysmorphic disorder (BDD) is a somatoform disorder characterized by the patient’s excessive concern with an imagined or minor defect in physical appearance. Patients with BDD often have been observed in aesthetic surgery settings seeking surgical enhancement at a reported prevalence of 6% to 15%. Published studies in the general population tend to aggregate a prevalence of 0.7% to 2.3%. This review aimed to search the literature for data on the prevalence, psychopathologic aspects, and comorbidity of BDD, and to provide an update on current BDD research. Relevant literature was identified by searching the Medline, PubMed, PsycINFO, and EMBASE databases. The following search words were used alone or in combination when appropriate: “body dysmorphic disorder,” “somatoform disorder,” “obsessive compulsive spectrum disorder,” “personality disorders,” “presurgical counseling,” “aesthetic surgery,” “cosmetic surgery,” and “plastic surgery.” Further articles were sourced from the reference lists of the articles ascertained through the search. Recent findings include the relationship between BDD and the obsessive-compulsive spectrum, treatment of BDD based on pharmacologic and psychological approaches, and the hypothesis that the often distinguished delusional and nondelusional variants of BDD very likely are the expression of a single disorder with varying degrees of severity. Retrospective outcome studies suggest that patients affected by BDD typically do not benefit from surgical treatment. In contrast, serotonin reuptake inhibitors and cognitive-behavior therapy appear to be good practice in addressing the disorder. Further research is needed to identify effective interventions for patients who do not respond to these treatment methods.

Nanotechnology-based therapies for skin wound regeneration

The cutting-edge combination of nanotechnology with medicine offers the unprecedented opportunity to create materials and devices at a nanoscale level, holding the potential to revolutionize currently available macroscale therapeutics. Nanotechnology already provides a plethora of advantages to medical care, and the success of nanoparticulate systems suggests that a progressive increase in the exploration of their potential will take place in the near future. An overview on the current applications of nanotechnology to wound healing and wound care is presented.

Successful recellularization of human tendon scaffolds using adipose-derived mesenchymal stem cells and collagen gel.

The major goal of regenerative medicine is to determine experimental techniques that take maximal advantage of reparative processes that occur naturally in the animal body. Injection of mesenchymal stem cells into the core of a damaged tendon represents such an approach. Decellularization of native tendons as potential targets and seeding protocols are currently under investigation. The aim of our study was to manufacture a recellularized biocompatible scaffold from cadaveric tissue for use in total or partial tendon injuries. Results showed that it was possible to introduce proliferating cells into the core of a decellularized tendon to treat the scaffold with a collagen gel. The method was effective in maintaining scaffold extracellular matrix and for expressing collagen type I and cartilage oligomeric matrix protein by injecting mesenchymal stem cells. Copyright