The discovery of several unexpected complex biological roles of hyaluronic acid (HA) has promoted new research impetus for biologists and, the clinical interest in several fields of medicine, such as ophthalmology, articular pathologies, cutaneous repair, skin remodeling, vascular prosthesis, adipose tissue engineering, nerve reconstruction and cancer therapy. In addition, the great potential of HA in medicine has stimulated the interest of pharmaceutical companies which, by means of new technologies can produce HA and several new derivatives in order to increase both the residence time in a variety of human tissues and the anti-inflammatory properties. Minor chemical modifications of the molecule, such as the esterification with benzyl alcohol (Hyaff-11® biomaterials), have made possible the production of water-insoluble polymers that have been manufactured in various forms: membranes, gauzes, nonwoven meshes, gels, tubes. All these biomaterials are used as wound-covering, anti-adhesive devices and as scaffolds for tissue engineering, such as epidermis, dermis, micro-vascularized skin, cartilage and bone. In this review, the essential biological functions of HA and the applications of its derivatives for pharmaceutical and tissue regeneration purposes are reviewed.

No abstract

The aim of this study was to develop a prosthetic graft that could perform as a small-diameter vascular conduit for vein regeneration. The difficulty of obtaining significant long-term patency and good wall mechanical strength in vivo has been a significant obstacle in achieving small-diameter vein prostheses. Fifteen Male Wistar rats weighing 250-350 g were used. Tubular structures of hyaluronan (HYAFF-11 tubules, 2 mm diameter, and 1.5 cm length) were implanted in the vena cava of rats as temporary absorbable guides to promote regeneration of veins. Performance was assessed at 30, 60, and 90 days after surgery by histology (hematoxylin-eosin and Weighert solution) and immunohistochemistry (antibodies to von Willebrand factor and to Myosin Light-Chain Kinase). These experiments resulted in two novel findings: (1) sequential regeneration of vascular components led to complete vein wall regeneration 30 days after surgery; (2) the biomaterial used created the ideal environment for the delicate regeneration process during the critical initial phases, yet its biodegradability allowed for complete degradation of the construct 4 months after implantation, at which time, a new vein remained to connect the vein stumps. This work demonstrates the complete vena cava regeneration inside the hyaluronic acid-based prosthesis, opening new perspective of microsurgical applications, like replantation of the upper limb, elongation of vascular pedicle of free flaps, cardiovascular surgery, and pediatric microvascular surgery.

Background Capsular contracture (CC) represents one of the most common complications in breast reconstruction surgery, impairing final result and patients’ well-being. The role of acellular dermal matrixes (ADM) has been widely described for the treatment and prevention of contracture. The aim of the study was to evaluate the efficacy and safety of complete implant coverage with porcine-derived ADM in preventing CC limiting complications. In addition, patients’ reported outcomes were evaluated in order to define the role of ADM in improving sexual, physical and psychosocial well-being and satisfaction. Methods 42 patients who underwent surgical treatment of 46 contracted reconstructed breasts from May 2018th to May 2019th were collected in the two groups (ADM group vs. Control group). Results The ADM group showed lower rate of CC recurrence and a higher rate of implant losses and minor complications. A significant difference was observed in red breast syndrome (27.3% in the ADM group vs. absent in control the group) and skin ulceration rates (18.2% in the ADM group vs. 4.18% in the control group). As for patients’ perceived outcomes, the ADM group showed a statistically significant higher postoperative Satisfaction of Breast Scale score compared to the control group. In addition, a significant difference was observed in the improvement of Physical Well-Being of the Chest Scale and the Satisfaction of Breast Scale after surgery, in favor to the ADM group. Conclusion Complete implant coverage with ADM may reduce the risk of CC recurrence in breast reconstruction. An accurate patient selection allows minimizing complications improving patient well-being and satisfaction. Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

We are sitting on the cusp of the bioengineered breast era, in which implant-based breast reconstruction is seeing a growing trend and biotechnology research progressively empowers clinical practice. As never before, the choice of biomaterials has acquired great importance for achieving reconstructive outcomes, and the increase in the use of acellular dermal matrices (ADMs) in the field of senology tells us a story of profound upheaval and progress. With the advent of prepectoral breast reconstruction (PPBR), plenty of devices have been proposed to wrap the silicone prosthesis, either completely or partially. However, this has caused a great deal of confusion and dissent with regard to the adoption of feasible reconstructive strategies as well as the original scientific rationale underlying the prepectoral approach. Braxon® is the very first device that made prepectoral implant positioning possible, wrapping around the prosthesis and exerting the proven ADM regenerative potential at the implant–tissue interface, taking advantage of the body's physiological healing mechanisms. To date, the Braxon® method is among the most studied and practiced worldwide, and more than 50 publications confirm the superior performance of the device in the most varied clinical scenarios. However, a comprehensive record of the working of this pioneering device is still missing. Therefore, our aim with this review is to lay a structured knowledge of surgery with BRAXON® and to provide a decision-making tool in the field of PPBR through a complete understanding on the very first device for prepectoral, one decade after its introduction.