Giorgio Giatsidis

Electromyography data for non-invasive naturally-controlled robotic hand prostheses

Recent advances in rehabilitation robotics suggest that it may be possible for hand-amputated subjects to recover at least a significant part of the lost hand functionality. The control of robotic prosthetic hands using non-invasive techniques is still a challenge in real life: myoelectric prostheses give limited control capabilities, the control is often unnatural and must be learned through long training times. Meanwhile, scientific literature results are promising but they are still far from fulfilling real-life needs. This work aims to close this gap by allowing worldwide research groups to develop and test movement recognition and force control algorithms on a benchmark scientific database. The database is targeted at studying the relationship between surface electromyography, hand kinematics and hand forces, with the final goal of developing non-invasive, naturally controlled, robotic hand prostheses. The validation section verifies that the data are similar to data acquired in real-life conditions, and that recognition of different hand tasks by applying state-of-the-art signal features and machine-learning algorithms is possible.

The role of gene therapy in regenerative surgery: updated insights.

Background: In the past two decades, regenerative surgeons have focused increasing attention on the potential of gene therapy for treatment of local disorders and injuries. Gene transfer techniques may provide an effective local and short-term induction of growth factors without the limits of other topical therapies. In 2002, Tepper and Mehrara accurately reviewed the topic: given the substantial advancement of research on this issue, an updated review is provided. Methods: Literature indexed in the National Center for Biotechnology Information database (PubMed) has been reviewed using variable combinations of keywords (“gene therapy,” “regenerative medicine,” “tissue regeneration,” and “gene medicine”). Articles investigating the association between gene therapies and local pathologic conditions have been considered. Attention has been focused on articles published after 2002. Further literature has been obtained by analysis of references listed in reviewed articles. Results: Gene therapy approaches have been successfully adopted in preclinical models for treatment of a large variety of local diseases affecting almost every type of tissue. Experiences in abnormalities involving skin (e.g., chronic wounds, burn injuries, pathologic scars), bone, cartilage, endothelia, and nerves have been reviewed. In addition, the supporting role of gene therapies to other tissue-engineering approaches has been discussed. Despite initial reports, clinical evidence has been provided only for treatment of diabetic ulcers, rheumatoid arthritis, and osteoarthritis. Conclusions: Translation of gene therapy strategies into human clinical trials is still a lengthy, difficult, and expensive process. Even so, cutting-edge gene therapy–based strategies in reconstructive procedures could soon set valuable milestones for development of efficient treatments in a growing number of local diseases and injuries.

Induction of Adipogenesis by External Volume Expansion.

Background: External volume expansion by suction is used to prepare the recipient site for fat grafting by increasing its compliance and vascularity. The authors previously developed a mouse model for external volume expansion and demonstrated its pro-proliferative and angiogenic effects. Increased thickness of the subcutaneous tissue was also observed. This study was thus designed to assess the adipogenic potential of external volume expansion stimulation. Methods: A miniaturized external volume expansion device consisting of a rubber dome connected to a −25 mmHg suction source was applied to the dorsum of mice for a single 2-hour stimulation or for 2 hours daily for 5 days. Tissues were harvested up to 48 hours after the last stimulation and analyzed for edema, inflammation, and adipocyte content by staining for hematoxylin and eosin, CD45, and perilipin-A. Expression of peroxisome proliferator-activated receptor-&ggr; (proadipogenic factor) and preadipocyte factor 1 (preadipocyte marker) was evaluated by Western blot analysis. Results: Both a 2-hour stimulation and cyclical 2-hour stimulation for 5 days induced 1.5- and 1.9-fold increases in the number of adipocytes per millimeter. Edema was present in the immediate poststimulation period, and inflammation was seen 2 days later. Peroxisome proliferator-activated receptor-&ggr; was increased at the end of stimulation. Conclusions: Stretch is known to stimulate proliferation, whereas edema and inflammation are both emerging proadipogenic factors. Their combination in external volume expansion seems to produce proadipogenic effects, seen even after a single 2-hour stimulation.

Facial basal cell carcinoma: analysis of recurrence and follow-up strategies.

Rates of recurrence after incomplete surgical excision of basal cell carcinoma (BCC) range from 4 to 16.6% of analyzed cases. The aim of the present study was to identify the predictive factors associated with facial BBC recurrence following excision and their influences, in order to establish a proper therapeutic strategy. A monocentric retrospective study was performed reviewing all BCCs surgically excised at the Institute of Plastic Surgery, University of Padua, with particular focus on the involvement of surgical margins and recurrence. Seven hundred and nineteen lesions in 605 patients were studied. Correlations between recurrence probability and various characteristics of BCC were analyzed using a logistic regression model. It was observed that incomplete excision, deep margin involvement, the presence of sclerodermiform or metatypic basaloid squamous cells, as well as pleomorphous histological variants and/or peritumoral inflammatory infiltrates, were all related to an increase in the probability of recurrence. BCC excision must be followed by individualized management with particular consideration for the localization, the histological type and other known predisposing factors; the treatment strategy and, in particular, the length of the surveillance period and the frequency of patient assessment should be evaluated on the basis of the recurrence probability outlined.

Skin Substitutes and Bioscaffolds : Temporary and Permanent Coverage

Advancements in surgical wound treatment have led to skin substitutes and bioscaffolds as temporary and permanent coverage for burn wounds. Skin substitutes are used to improve wound coverage and restore the functional and aesthetic qualities of skin, and help to prevent wound infection and maintain a moist wound healing environment. Although allografts are preferred when autografts are not possible, high costs and limited availability have led to the use of xenografts and the development of skin substitutes and bioscaffolds. Despite constant evolution in the development of these skin substitutes and bioscaffolds, no single product stands out as the gold standard.

Fascia lata allografts as biological mesh in abdominal wall repair: preliminary outcomes from a retrospective case series.

Background: The use of biological meshes in management of infected abdominal hernias or in abdominal fields at high risk of infection (potentially contaminated or with relevant comorbidities) is well established. Available products include xenogenic patches or decellularized dermal allografts. Despite their biomechanical features, banked fascial allografts have not been investigated yet in this setting. The authors evaluated the safety and effectiveness of banked fascia lata allografts as biological meshes in abdominal wall repair. Methods: A consecutive series of patients affected by abdominal wall defects and who were candidates for repair by means of a biological mesh and treated in the authors’ institution with banked fascia lata allografts were reviewed retrospectively. Data from clinical and instrumental follow-up evaluations up to 48 months (average, 23 months) were analyzed. Results: Twenty-one patients (aged 1 to 86 years) with abdominal wall defects resulting from traumatic (n = 1), neoplastic (n = 6), or multiple previous laparotomies (n = 14) were treated from January of 2008 to October of 2012. Operations had no relevant postoperative complications. At clinical/instrumental follow-up examinations, no major signs of recurrence, laxity, infection of grafts, or other related pathologic symptoms were recorded. Three patients suffered from temporary minor complications (e.g., wound seroma, partial cutaneous dehiscence). At instrumental (computed tomographic scan or magnetic resonance imaging) evaluations, the neofascial tissue appeared stable until medium-term follow-up (3 to 6 months), later being gradually degraded and apparently replaced by host tissue. Conclusion: According to limited preliminary outcomes, banked fascia lata allografts seem to provide a biocompatible, safe, and effective alternative to other biological meshes. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Drug delivery systems and materials for wound healing applications

Chronic, non-healing wounds place a significant burden on patients and healthcare systems, resulting in impaired mobility, limb amputation, or even death. Chronic wounds result from a disruption in the highly orchestrated cascade of events involved in wound closure. Significant advances in our understanding of the pathophysiology of chronic wounds have resulted in the development of drugs designed to target different aspects of the impaired processes. However, the hostility of the wound environment rich in degradative enzymes and its elevated pH, combined with differences in the time scales of different physiological processes involved in tissue regeneration require the use of effective drug delivery systems. In this review, we will first discuss the pathophysiology of chronic wounds and then the materials used for engineering drug delivery systems. Different passive and active drug delivery systems used in wound care will be reviewed. In addition, the architecture of the delivery platform and its ability to modulate drug delivery are discussed. Emerging technologies and the opportunities for engineering more effective wound care devices are also highlighted.

Adipose‐derived aldehyde‐dehydrogenase‐expressing cells promote dermal regenerative potential with collagen‐glycosaminoglycan scaffold

Aldehyde dehydrogenase (ALDH) is an enzyme that plays an important role in retinoid metabolism and highly expressed in stem cells. This study isolated ALDH‐expressing cells from subcutaneous adipose tissue and investigated their potential to enhance healing in a full‐thickness skin wound in rats by co‐implanting them with collagen‐glycosaminoglycan (c‐GAG) scaffolds. ALDH‐positive cells were isolated by a fluorescence‐activated cell sorting technique from Lewis rats stromal‐vascular‐fraction (SVF) and transplanted with c‐GAG scaffolds in a rat full‐thickness skin wound model. At 7 days after surgery, the microscopic appearance of c‐GAG scaffolds seeded with ALDH‐positive was compared with those of uncultured‐SVF, and cultured‐SVF adipose‐derived stromal cells (ASCs). The thickness of cellular ingrowth in the ASC group (630 ± 180 μm) was significantly thicker than that in the control (390 ± 120 μm) or SVF (380 ± 140 μm) groups, but non‐significantly thicker than that in the ALDH‐positive group (570 ± 220 μm). The thickness of regenerated collagen layer was significantly thicker in the ALDH‐positive group (160 ± 110 μm) than in the ASCs (81 ± 41 μm), the control (65 ± 24 μm), or SVF (64 ± 34 μm) groups. Immunofluorescent staining with CD31 proved that transplanted ALDH‐positive cells differentiated into vascular endothelial cells in c‐GAG scaffolds. Combined transplantation with c‐GAG scaffolds and adipose‐derived ALDH‐positive cells promoted dermal regeneration, giving a possibility that ALDH‐positive cells would greatly shorten the waiting period before secondary autologous skin grafting was possible.

Anisotropic architecture and electrical stimulation enhance neuron cell behaviour on a tough graphene embedded PVA: alginate fibrous scaffold

Tough scaffolds comprised of aligned and conductive fibers are promising for peripheral nerve regeneration due to their unique mechanical and electrical properties. Several studies have confirmed that electrical stimulation can control the axonal extension in vitro. However, the stimulatory effects of scaffold architecture and electrical stimulation have not yet been investigated in detail. Here, we assessed a comparison between aligned and random fibers made of graphene (Gr) embedded sodium alginate (SA) polyvinyl alcohol (PVA) (Gr-AP scaffolds) for peripheral nerve engineering. The effects of applied electrical stimulation and orientation of the fabricated fibers on the in vitro attachment, alignment, and proliferation of PC12 cells (a rat neuronal cell line) were investigated. The results revealed that the aligned fibrous Gr-AP scaffolds closely mimicked the anisotropic structure of the native sciatic nerve. Aligned fibrous Gr-AP scaffolds significantly improved mechanical properties as well as cell-scaffold integration compared to random fibrous scaffolds. In addition, electrical stimulation significantly improved PC12 cell proliferation. In summary, our findings revealed that aligned fibrous Gr-AP scaffolds offered superior mechanical characteristics and structural properties that enhanced neural cell–substrate interactions, resulting in a promising construct for nerve tissue regeneration.

Moderate-intensity Intermittent External Volume Expansion Optimizes the Soft-tissue Response in a Murine Model.

Background: Intermittent external volume expansion using suction enhances the vascular network of soft tissues, possibly increasing fat graft survival. However, the optimal kinetics of application have not been determined. Based on their previous experience, the authors hypothesized that moderate-intensity intermittent external volume expansion application may further enhance both the angiogenic and adipogenic potential. Methods: Fifty 12-week-old wild-type mice were assigned to five experimental groups (n = 10 per group) and underwent five different intermittent applications of external volume expansion (i.e., single-application control, low-intensity, moderate-intensity, and two groups of high-intensity). Five days after the final stimulation, skin biopsy specimens were obtained from stimulated and contralateral nonstimulated areas. Microscopic sections were analyzed for angiogenesis, skin remodeling, and adipogenesis. Results: Moderate-intensity intermittent stimulation (0.5 hour, 6 times/day for 5 days at −25 mmHg suction) almost doubled cutaneous vascular density (1.9-fold increase), induced skin thickening (1.9-fold increase), and expanded the subcutaneous tissue (2.3-fold increase) compared with control. External volume expansion kinetics did not affect tissue inflammation at 5 days after treatment. High-intensity intermittent stimulations also increased the density of blood vessels (1.6-fold increase compared with controls) but caused tissue damage, whereas low-intensity external volume expansion did not induce significant changes. Conclusion: Application of moderate-intensity intermittent external volume expansion optimizes induction of angiogenesis and adipogenesis in soft tissues without tissue damage, holding potential for time-effective recipient-site preconditioning before fat grafting.