Polymeric Biomaterials for Wound Healing Incorporating Plant Extracts and Extracellular Matrix Components

Biomaterials are constructed to promote or stimulate the processes of wound healing. Polymeric biomaterials can be used to hydrate the wound and serve as barrier to pathogens with plant extracts, antimicrobial agents and extracellular components incorporated to stimulate the healing process. The biological and physical augmentation provided by extracellular matrix derived implants continues facilitate innovation in biomaterials utilized in management of nonhealing wounds. Tissue-processing methodologies can birth extracellular matrix-based devices with characteristic post-implantation responses ranging from the classic foreign body encapsulation of a permanent implant, to one where the implant is degraded and resorbed, to one where the processed extracellular matrix implant is populated by local fibroblasts and supporting vasculature to produce, a viable and metabolically active tissue. Extracellular matrix components and plant extracts have been shown to possesses pharmacological properties with potential for use in the treatment of skin diseases and wound healing. Antioxidant, anti-inflammatory assays, and wound healing assays have been shown to support the dermatological and wound healing usage of these medicinal plants extracts.

Principles for Controlling the Shape Recovery and Degradation Behavior of Biodegradable Shape-Memory Polymers in Biomedical Applications

Polymers with the shape memory effect possess tremendous potential for application in diverse fields, including aerospace, textiles, robotics, and biomedicine, because of their mechanical properties (softness and flexibility) and chemical tunability. Biodegradable shape memory polymers (BSMPs) have unique benefits of long-term biocompatibility and formation of zero-waste byproducts as the final degradable products are resorbed or absorbed via metabolism or enzyme digestion processes. In addition to their application toward the prevention of biofilm formation or internal tissue damage caused by permanent implant materials and the subsequent need for secondary surgery, which causes secondary infections and complications, BSMPs have been highlighted for minimally invasive medical applications. The properties of BSMPs, including high tunability, thermomechanical properties, shape memory performance, and degradation rate, can be achieved by controlling the combination and content of the comonomer and crystallinity. In addition, the biodegradable chemistry and kinetics of BSMPs, which can be controlled by combining several biodegradable polymers with different hydrolysis chemistry products, such as anhydrides, esters, and carbonates, strongly affect the hydrolytic activity and erosion property. A wide range of applications including self-expending stents, wound closure, drug release systems, and tissue repair, suggests that the BSMPs can be applied as actuators on the basis of their shape recovery and degradation ability.

Breast Reconstruction and Post Mastectomy Radiotherapy: A Primer for Members of a Multidisciplinary Team

Background: Post-mastectomy radiation therapy (PMRT) is a key component in managing breast cancer with increased potential for locoregional recurrence. Breast reconstruction has evolved to include various techniques that can be categorized according to the type of reconstruction (implant-based versus autologous reconstruction), and the timing of reconstruction (one versus two-step techniques). Methods/Results: This review article aims to provide a digestible summary of PMRT in the context of breast reconstruction by summarizing salient existing literature with a focus on considerations of the plastic surgeon. The main findings summarized in this review include the technique and timing of breast reconstruction, how breast reconstruction can affect radiation delivery, and the type of reconstruction. Within implant-based reconstruction, existing data on the location of the implant in the context of PMRT and PMRT delivery to the tissue expander versus permanent implant are reviewed. Each consideration may alter the probability of successful reconstruction and patient satisfaction.Conclusion: It is essential for the multidisciplinary breast cancer team to have knowledge of the various reconstructive options, and to understand the safety and comparative effectiveness of staged reconstruction in the setting of PMRT. Additionally, one must consider that reconstructive procedures may have implications on the timely administration of PMRT. This review serves as a reference for members of the oncologic care team when discussing reconstructive options with patients who will receive PMRT as part of their treatment plan.

Novel Pre-Mastectomy Permanent Implant Reconstruction

Background: Breast reconstruction has been shown to have significant psychosocial benefits for breast cancer patients. Multiple techniques have been used to improve patient satisfaction, aesthetic outcomes, and decrease complications. However, while these techniques are advantageous, they have some significant disadvantages. We are presenting a novel two-stage, pre-mastectomy permanent implant reconstruction (PPIR) technique in an attempt to overcome some of these disadvantages. Methods: Five patients met the essential criteria: they underwent PPIR by insertion of silicone implants three weeks before a proposed mastectomy. The Short Form-36 quality of life questionnaire and the Michigan Breast Reconstruction Outcomes Survey were used before and after the surgery to assess outcome and patient satisfaction. Paired sample t-tests were used to compare changes in the survey scores for various psychosocial subscales and to determine whether score changes after reconstruction were significant. Result: Five patients underwent seven breast reconstructions using PPIR. None of the patients experienced surgical complications (e.g. mastectomy flap complication, wound dehiscence, surgical site infection, or implant-related complications). The PPIR technique resulted in improved psychosocial outcomes and body image with high patient satisfaction. Conclusion: Pre-mastectomy permanent implant reconstruction is a promising potential technique with good aesthetic outcome and patient satisfaction that carries no tissue expander complications and eliminates multiple clinic visits and the usage of a dermal substitute.

A Randomized Controlled Trial Comparing Alloderm-RTU with DermACELL in Immediate Subpectoral Implant-Based Breast Reconstruction

Background: The effectiveness of different acellular dermal matrices (ADM) used for implant-based reconstruction immediately following mastectomy is an important clinical question. A prospective randomized clinical trial was performed to evaluate the superiority of DermACELL over Alloderm-RTU in reducing drain duration. Methods: Patients undergoing mastectomy with subpectoral immediate and permanent implant-based breast reconstruction were randomized to Alloderm-RTU or DermACELL. The primary outcome was seroma formation, measured by the duration of postoperative drain placement. Secondary outcomes included: post drain removal seroma aspiration, infection, redbreast syndrome, wound dehiscence, loss of the implant, and unplanned return to the operating room. Results: 62 patients were randomized for 81 mastectomies (41 Alloderm-RTU, 40 DermACELL). Baseline characteristics were similar. There was no statistically significant difference in mean drain duration (p = 0.16), with a trend towards longer duration in the Alloderm-RTU group (1.6 days; 95%CI, 0.7 to 3.9). The overall rate of minor and major complications were statistically similar between the two groups; although patients with Alloderm-RTU had 3 times as many infections requiring antibiotics (7.9% vs. 2.5%) with a risk difference of 5.4 (95%CI −4.5 to 15.2), and twice as many unplanned returns to the operating room (15.8% vs. 7.5%) with a risk difference of 8.3 (95% CI −5.9 to 22.5) as DermACELL. Conclusion: This is the first prospective randomized clinical trial comparing the two most commonly used human-derived ADMs. There was no statistically significant difference in drain duration, minor, or major complications between DermACELL over Alloderm-RTU in immediate subpectoral permanent implant-based breast reconstruction post-mastectomy.

Effect of Solution Treatment on Microstructure and Mechanical Hardness of Ti-6Al-7Nb

The metastable β Ti-6Al-4V alloy has been used clinically as a permanent implant material owing to its suitable mechanical properties and biocompatibility. However, the alloying element V was accused of causing toxicity when released to human body fluid. In this work, Nb was used in the alloy to replace V. This study presents the characterization of microstructure and mechanical hardness of as-cast Ti-6Al-7Nb and after solution treatment. The Ti-6Al-7Nb alloy was fabricated by the centrifugal casting method. Solution treatment was carried out at 970°C for 1 hour, followed by oil quenching, and consecutively an aging treatment was applied at 500°C for 8 hours. The microstructure was studied by an optical microscope. The mechanical hardness was measured by microhardness Vickers. The results show that the mechanical hardness of the Ti-6Al-7Nb decreased from 396.2 to 377.2 HV as a result of the solution treatment. Reduction in the hardness was attributed to the phase transformation of α to the β phase during the solution treatment. The XRD analysis showed a reduction in the intensity of α phases at the (011), (012), and (020) planes in the alloy after the solution treatment. The results indicated that the microstructure and mechanical hardness of Ti-6Al7-Nb alloy were affected by the solution treatment.