The Use of Solid Sodium Silicate as Activator for an Amorphous Wollastonitic Hydraulic Binder.

To ensure the acceptable mechanical strength of amorphous wollastonitic hydraulic binders (AWHs), activation with a sodium silicate solution is necessary. However, the use of this type of activator increases the final cost and the complexity of the product's overall use. In this work, we focus on enhancing the manufacturing of the alkaline activator by producing three Na2SiO3 powders using cost-effective raw materials. The procedure consisted of heating a mixture of NaOH pebbles with either sand, glass, or diatomite to a temperature of 330 °C for 2 h. After synthesis, the powders were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD) techniques. Finally, mortars made with AWHs were activated using the synthesized powders that were added either as a solid or dissolved in an aqueous solution. The compressive strength results in these mortars show that the lab-made activators are competitive with the traditional sodium silicate activators. Furthermore, the synthetized activators can be added in either solid form or pre-dissolved in a solution. This innovative approach represents a more economical, sustainable and easy-to-use approach to enhancing the competitiveness of AWHs.

Prevascularized spongy-like hydrogels maintain their angiogenic potential after prolonged hypothermic storage.

The chronic shortage of organs and tissues for transplantation represents a dramatic burden on healthcare systems worldwide. Tissue engineering offers a potential solution to address these shortages, but several challenges remain, with prevascularization being a critical factor for in vivo survival and integration of tissue engineering products. Concurrently, a different challenge hindering the clinical implementation of such products, regards their efficient preservation from the fabrication site to the bedside. Hypothermia has emerged as a potential solution for this issue due to its milder effects on biologic systems in comparison with other cold preservation methodologies. Its impact on prevascularization, however, has not been well studied. In this work, 3D prevascularized constructs were fabricated using adipose-derived stromal vascular fraction cells and preserved at 4 °C using Hypothermosol or basal culture media (α-MEM). Hypothermosol efficiently preserved the structural and cellular integrity of prevascular networks as compared to constructs before preservation. In contrast, the use of α-MEM led to a clear reduction in prevascular structures, with concurrent induction of high levels of apoptosis and autophagy at the cellular level. In vivo evaluation using a chorioallantoic membrane model demonstrated that, in opposition to α-MEM, Hypothermosol preservation retained the angiogenic potential of constructs before preservation by recruiting a similar number of blood vessels from the host and presenting similar integration with host tissue. These results emphasize the need of studying the impact of preservation techniques on key properties of tissue engineering constructs such as prevascularization, in order to validate and streamline their clinical application.

Generation of 3D melanoma models using an assembloid-based approach.

While 3D tumor models have greatly evolved over the past years, there is still a strong requirement for more biosimilar models which are capable of recapitulating cellular crosstalk within the tumor microenvironment while equally displaying representative levels of tumor aggressiveness and invasion. Herein, we disclose an assembloid melanoma model based on the fusion of individual stromal multicellular spheroids (MCSs). In contrast to more traditional tumor models, we show that it is possible to develop self-organizing, heterotypic melanoma models where tumor cells present stem-cell like features like up-regulated pluripotency master regulators SOX2, POU5F1 and NANOG. Additionally, these assembloids display high levels of invasiveness while embedded in 3D matrices as evidenced by stromal cell promotion of melanoma cell invasion via metalloproteinase production. Furthermore, sensitivity to anticancer drug doxorubicin was demonstrated for the melanoma assembloid model. These findings suggest that melanoma assembloids may play a significant role in the field of 3D cancer models as they more closely mimic the tumor microenvironment when compared to more traditional MCSs, opening the doors to a better understanding of the role of tumor microenvironment in supporting tumor progression. STATEMENT OF SIGNIFICANCE: The development of complex 3D tumor models that better recapitulate the tumor microenvironment is crucial for both an improved comprehension of intercellular crosstalk and for more efficient drug screening. We have herein developed a self-organizing heterotypic assembloid-based melanoma model capable of closely mimicking the tumor microenvironment. Key features recapitulated were the preservation of cancer cell stemness, sensitivity to anti-cancer agents and tumor cell invasion promoted by stromal cells. The approach of pre-establishing distinct stromal domains for subsequent combination into more complex tumor constructs provides a route for developing superior tumor models with a higher degree of similarity to native cancer tissues.

Novel Amorphous-Wollastonitic Low-Calcium Hydraulic Binders: A State-of-the-Art Review.

Because of the severe environmental impact of the CO2 emissions associated with the production of ordinary Portland cement (OPC) and the increasing demand for this commodity material, the development of alternative products has become a global concern. One alternative to OPC, or alitic-based clinkers, are amorphous-wollastonitic low-calcium hydraulic binders (AWLCs). This new class of hydraulic binders, described in the literature for the first time in 2015, may significantly reduce the CO2 emissions associated with its production, resulting from its lower calcium content, but also from the fact that its production technology can be fully electrified. In this paper, a state-of-the-art review is presented, providing a comprehensive description of the latest research, summarizing both the physicochemical and mechanical characteristics of this type of hydraulic binder, as well as possible routes for its production at an industrial scale.

Pre-selection of fibroblast subsets prompts prevascularization of tissue engineered skin analogues.

The papillary and reticular dermis harbors phenotypically distinct fibroblasts, whose functions such as maintenance of skin's microvasculature are also distinct. Thus, we hypothesized that pre-selection of the subpopulations of fibroblasts would benefit the generation of skin tissue engineered (TE) constructs, promoting their prevascularization in vitro. We first isolated papillary and reticular fibroblasts using fluorescence-activated cell sorting and studied the effect of their secretome and extracellular matrix (ECM) on human dermal microvascular endothelial cell (hDMEC) organization. Subsequently, we developed a bilayered 3D polymeric structure with distinct layer-associated features to house the subpopulations of fibroblasts, to generate a skin analogue. Both papillary and reticular fibroblasts were able to stimulate capillary-like network formation in a Matrigel assay. However, the secretome of the two subpopulations was substantially different, being enriched in VEGF, IGF-1, and Angio-1 in the case of papillary fibroblasts and in HGF and FGF-2 for the reticular subset. In addition, the fibroblast subpopulations deposited varied levels of ECM proteins, more collagen I and laminin was produced by the reticular subset, but these differences did not impact hDMEC organization. Vessel-like structures with lumens were observed earlier in the 3D skin analogue prepared with the sorted fibroblasts, although ECM deposition was not affected by the cell's pre-selection. Moreover, a more differentiated epidermal layer was obtained in the skin analogue formed by the sorted fibroblasts, confirming that its whole structure was not affected. Overall, we provide evidence that pre-selection of papillary and reticular fibroblasts is relevant for promoting the in vitro prevascularization of skin TE constructs.

Stromal Vascular Fraction Obtained From Subcutaneous Adipose Tissue: Ex-Obese and Older Population as Main Clinical Targets.

INTRODUCTION: Human adipose tissue contains a heterogeneous and synergistic mixture of cells called stromal vascular fraction (SVF) with highly proliferative and angiogenic properties, conferring promising applicability in the field of regenerative medicine. This study aims to investigate if age, body mass index (BMI), history of obesity and massive weight loss, and harvest site are related to SVF cell marker expression. METHODS: A total of 26 samples of subcutaneous adipose tissue were harvested from patients admitted to the Plastic and Reconstructive department in University Hospital Center of São João, Porto, Portugal, for body contouring surgery. The percentage of cells expressing CD31, CD34, CD45, CD73, CD90, and CD105 was assessed and compared with patient's age, BMI, history of obesity and massive weight loss (ex-obese group), and harvest site. RESULTS: In the ex-obese group, a significantly higher number of cells expressing CD90 (P = 0.002) was found. BMI, harvest site, and age appear to have no association with SVF subpopulations. CONCLUSIONS: This study suggests that ex-obese patients have a higher percentage of SVF cells expressing CD90, which correlates with higher proliferative and angiogenic rates. The effect of former obesity and massive weight loss on the expression of CD90 is a new and relevant finding because it makes this population a suitable candidate for reconstructive and aesthetic surgery and other fields of regenerative medicine. The use of SVF appears also promising in older patients because no negative correlation between increasing age and different cell markers expression was found.

Successful Surgical Resection and Reconstruction of a Giant Facial Vascular Malformation in an Elderly Patient.

Venous vascular malformations can be challenging, especially in an elderly patient. As these lesions can present with ulceration, deformity, pain, and swelling resulting from thrombi formed due to low flow (palpable phleboliths), removing them can be important for the well-being of the patient. A 79-year-old patient presented with a giant venous malformations occupying the left hemiface and a deprivation amblyopia in his left eye. Successful surgical resection and reconstruction was achieved and the patient was very pleased with his new appearance. Despite his age and surgical risks, we consider that never is late to improve a disfigured face.

Role of the Plastic Surgeon in Tuberculosis Treatment.

Background: Tuberculous empyema is rare. Its treatment requires oral antituberculous drugs, empyema drainage, and in severe cases, decortication and pneumectomy. In the presence of tuberculosis, lung resection has a high risk of postoperative bronchopleural fistula (BPF) and empyema. Treatment includes drainage, fistula occlusion, dead space obliteration, and infection control. Muscle flap transfer allows BPF occlusion and dead space obliteration. Methods: This report presents a case of a 63-year-old man with tuberculosis and postoperative BPF with empyema after pleural decortication and left lower lobe resection. The empyema was drained, and antituberculous drugs were started. The BPF was occluded with a latissimus dorsi and serratus anterior chimeric muscle flap, and the remaining thoracic dead space and chest wall defect were reconstructed with a pedicled pectoralis major myocutaneous flap. Results: Healing occurred uneventfully, and the patient was discharged from the hospital after 2 weeks. Conclusions: This type of thoracic defect is rare nowadays, especially in the setting of tuberculous infections. Although workhorse flaps like latissimus dorsi or pectoralis major flaps have been progressively surpassed by more elegant solutions like fasciocutaneous pedicled flaps and free flaps, they must still be considerations in the decision-making process of a reconstructive surgeon, and flap choice must be made on a case-by-case basis.

Incidence and outcomes of thromboembolic events in plastic surgery infirmary patients.

INTRODUCTION: This study was developed to determine the incidence and outcome of thromboembolic events in a plastic surgery infirmary. METHODS: In a retrospective study, using the hospital's software of statistics and database, we selected the patients admitted to the plastic surgery infirmary of Hospital São João, Porto- Portugal, from 2006 to the end of 2015. Using software diagnosis codification that is the same as the International Classification of Diseases, Ninth Revision (ICD-9), we selected patients that suffered a deep venous thrombosis or pulmonary embolism and reviewed their medical records - collected the number of patients submitted to abdominoplasty, head and neck cancer patients, and breast cancer patients. RESULTS: Of the 10,473 patients of the data set, nine patients were diagnosed with a venous thromboembolism (VTE) event, leading to a rate of 0.09% over the 10 years. During that period, 1728 abdominoplasties were performed, and there were three cases of VTE (0.17%); 338 head and neck cancer patients, three VTE events (0.9%), and one VTE (0.2%) in 506 breast cancer patients. CONCLUSION: This study suggests that in plastic surgery, VTE risk assessment and corresponding prophylaxis cannot be neglected.

INTRODUCCIÓN: Este estudio fue desarrollado para determinar la incidencia y el resultado de tromboembólicos eventos (TEV) en una enfermería de cirugía plástica. MÉTODOS: En un estudio retrospectivo, utilizando el software del hospital de estadísticas y base de datos, seleccionamos a los pacientes ingresados a la cirugía plástica enfermería del Hospital São João, Portugal, desde 2006 hasta finales de 2015. Usando una codificación de diagnóstico de software que es la misma que la Clasificación Internacional de Enfermedades, Novena Revisión (CIE-9), pacientes seleccionados que sufrieron una trombosis venosa profunda o embolia pulmonar y revisó sus registros médicos, recopilados el número de pacientes sometidos a abdominoplastia, cabeza y cuello pacientes con cáncer y pacientes con cáncer de mama. RESULTADOS: De los 10473 pacientes del conjunto de datos, nueve pacientes fueron diagnosticados con un evento de TEV, lo que lleva a una tasa de 0,09% durante los diez años. Durante Eso período, se realizaron 1728 abdominoplasties, y hubo 3 casos de TEV (0,17%); 338 pacientes con cáncer de cabeza y cuello, 3 eventos de TEV (0,9%) y un TEV (0,2%) en 506 pacientes con cáncer de mama. CONCLUSIÓN: Este estudio sugiere que en la cirugía plástica, la evaluación del riesgo de TEV y la profilaxis correspondiente no puede ser descuidada.

Spongy-like hydrogels prevascularization with the adipose tissue vascular fraction delays cutaneous wound healing by sustaining inflammatory cell influx.

In vitro prevascularization is one of the most explored approaches to foster engineered tissue vascularization. We previously demonstrated a benefit in tissue neovascularization by using integrin-specific biomaterials prevascularized by stromal vascular fraction (SVF) cells, which triggered vasculogenesis in the absence of extrinsic growth factors. SVF cells are also associated to biological processes important in cutaneous wound healing. Thus, we aimed to investigate whether in vitro construct prevascularization with SVF accelerates the healing cascade by fostering early vascularization vis-à-vis SVF seeding prior to implantation. Prevascularized constructs delayed re-epithelization of full-thickness mice wounds compared to both non-prevascularized and control (no SVF) groups. Our results suggest this delay is due to a persistent inflammation as indicated by a significantly lower M2(CD163+)/M1(CD86+) macrophage subtype ratio. Moreover, a slower transition from the inflammatory to the proliferative phase of the healing was confirmed by reduced extracellular matrix deposition and increased presence of thick collagen fibers from early time-points, suggesting the prevalence of fiber crosslinking in relation to neodeposition. Overall, while prevascularization potentiates inflammatory cell influx, which negatively impacts the cutaneous wound healing cascade, an effective wound healing was guaranteed in non-prevascularized SVF cell-containing spongy-like hydrogels confirming that the SVF can have enhanced efficacy.

Growth Factor-Free Vascularization of Marine-Origin Collagen Sponges Using Cryopreserved Stromal Vascular Fractions from Human Adipose Tissue.

The successful integration of transplanted three-dimensional tissue engineering (TE) constructs depends greatly on their rapid vascularization. Therefore, it is essential to address this vascularization issue in the initial design of constructs for perfused tissues. Two of the most important variables in this regard are scaffold composition and cell sourcing. Collagens with marine origins overcome some issues associated with mammal-derived collagen while maintaining their advantages in terms of biocompatibility. Concurrently, the freshly isolated stromal vascular fraction (SVF) of adipose tissue has been proposed as an advantageous cell fraction for vascularization purposes due to its highly angiogenic properties, allowing extrinsic angiogenic growth factor-free vascularization strategies for TE applications. In this study, we aimed at understanding whether marine collagen 3D matrices could support cryopreserved human SVF in maintaining intrinsic angiogenic properties observed for fresh SVF. For this, cryopreserved human SVF was seeded on blue shark collagen sponges and cultured up to 7 days in a basal medium. The secretome profile of several angiogenesis-related factors was studied throughout culture times and correlated with the expression pattern of CD31 and CD146, which showed the formation of a prevascular network. Upon in ovo implantation, increased vessel recruitment was observed in prevascularized sponges when compared with sponges without SVF cells. Immunohistochemistry for CD31 demonstrated the improved integration of prevascularized sponges within chick chorioalantoic membrane (CAM) tissues, while in situ hybridization showed human cells lining blood vessels. These results demonstrate the potential of using cryopreserved SVF combined with marine collagen as a streamlined approach to improve the vascularization of TE constructs.

Integrin-specific hydrogels for growth factor-free vasculogenesis.

Integrin-binding biomaterials have been extensively evaluated for their capacity to enable de novo formation of capillary-like structures/vessels, ultimately supporting neovascularization in vivo. Yet, the role of integrins as vascular initiators in engineered materials is still not well understood. Here, we show that αvß3 integrin-specific 3D matrices were able to retain PECAM1+ cells from the stromal vascular fraction (SVF) of adipose tissue, triggering vasculogenesis in vitro in the absence of extrinsic growth factors. Our results suggest that αvß3-RGD-driven signaling in the formation of capillary-like structures prevents the activation of the caspase 8 pathway and activates the FAK/paxillin pathway, both responsible for endothelial cells (ECs) survival and migration. We also show that prevascularized αvß3 integrin-specific constructs inosculate with the host vascular system fostering in vivo neovascularization. Overall, this work demonstrates the ability of the biomaterial to trigger vasculogenesis in an integrin-specific manner, by activating essential pathways for EC survival and migration within a self-regulatory growth factor microenvironment. This strategy represents an improvement to current vascularization routes for Tissue Engineering constructs, potentially enhancing their clinical applicability.

Nasal Reconstruction: Reconstruction of a Nasal Tip, Columella and Middle Crura Defect After Human Bite with a Turn Down Flap Associated With Conchal Graft and Interpolated Melolabial Flap.

ABSTRACT: Nasal reconstruction is one of the most difficult procedures in plastic surgery due to its complex anatomy and function. A 31-year male was sent to our evaluation after an acquired nasal defect caused by a human bite 2 years before. The defect encompassed the nasal tip, columella, and both middle crura. After a detailed evaluation, the inner lining was reconstructed with a turndown flap of the released scar. In the same operative time, a shaped conchal cartilage graft was anchored to the remnants of both lateral crura and covered with a melolabial interpolated flap. Division, debulking, and final in setting of the flap was done after 5 weeks. Although simple steps were used, a good aesthetic reconstruction was achieved with minimal donor site morbidity.This case proves that a good planning is a cornerstone of a good reconstruction.

A Ruler for Abdominoplasty Preoperative Markings: The Potential of Best Scar Symmetry.

Background. Scar appearance is an important outcome in abdominoplasty surgery, and its asymmetry can have a significant impact on patient and surgeon satisfaction. Here, we compared the scar symmetry reached with a ruler specially designed for the preoperative marking in abdominoplasty to the classic preoperative incision marking. Methods. In this randomized, uni-blind study, 42 patients were allocated to 2 different groups. Group 1 patients had their preoperative marking made by a group of surgeons that used the classic technique as described by Baroudi (n = 21), and Group 2 patients received their preoperative marking by another group of surgeons, using a ruler specially designed to fit the abdominal contour (n = 21). Patients were evaluated using a standard questionnaire that collected information about general patient's characteristics. On the follow-up period, we evaluated the presence of late surgical complications, need for revision surgery, patient's satisfaction concerning the postoperative scar, and 4 distances were measured in both groups to assess symmetry. Statistical analysis was made. Results. A total of 42 patients underwent abdominoplasty and were evaluated on the follow-up period (mean time: 4 months). The mean difference of corresponding measures on each side (A-B vs. A-B' and A-C vs. A-C') was higher in Group 1 comparing to Group 2. The level of correlation between corresponding measurements was higher in Group 2. Better satisfaction regarding the scar symmetry was achieved in Group 2, being this result statistically significant (P = .004). Conclusions. The use of the specialized ruler may help surgeons achieve a better scar symmetry with higher patient satisfaction.

Dynamic Facial Reanimation in an Overweight Patient and with Significant Comorbidities: An Objective Analysis of Labbè Technique.

Gracilis free muscle transfer is considered the gold standard technique for facial reanimation in cases of facial palsy. However, it is limited by its long operative and recovery times, the need for a second surgical site, and its outcomes that can sometimes show midfacial bulk and oral commissure malposition. Facial reanimation with lengthening temporalis myoplasty (LTM)-Labbé technique- carries the advantage of having a shorter surgical time, a faster recovery, and being a less invasive surgery. Almost all patients included in studies of LTM were evaluated by subjective methods, and very little quantifiable data was available. A 64-year-old woman presented with long-standing incomplete right facial palsy secondary to acoustic neuroma surgery. Since she was overweight (body mass index [BMI]: 43.9) and had several cardiovascular comorbidities (hypertension, dyslipidemia), she was not a good candidate for gracilis free muscle transfer. She was submitted to facial reanimation with LTM. Fourteen months after surgery, she presented excellent facial symmetry, both at rest and in contraction, while smiling. She was evaluated with the Facegram-3D, a technology that we have developed for dynamic evaluation of facial muscle contraction. The analysis showed symmetry at rest and contraction, according to Terzis and Noah. Regarding vertical and horizontal displacement, the postoperative movement was synchronized and with less fluctuations when compared with the preoperative period. Notably, the anatomical pair's trajectories were smoother. Similar velocity profiles were found between anatomical pairs, with less abrupt changes in velocity values, further supporting improved movement control. Comparing the symmetry index, which takes a theoretical maximum of 1.0 for perfect 3D symmetry, its value was 0.56 for the commissures and 0.5 for the midpoints in the preoperative period, having improved to 0.91 and 0.82, respectively, 3 months postoperatively. Good aesthetic and functional results were achieved using the Labbè technique. LTM is a good option in cases of long-standing facial paralysis, if the patient desires a single-stage procedure with almost immediate dynamic function. Moreover, this technique assumes extreme importance in facial reanimation of patients of advanced age, overweight, or those who have several comorbidities.

Hand Transplantation-Risks and Benefits.

Composite tissue allotransplantation (CTA) is the culmination of progress in transplantation, allowing the reconstruction of the hand in amputees. Worldwide, more than 100 procedures have been performed. The aim of this work was to understand the hand allotransplantation approach, making known current aspects, risks, and benefits. A PubMed research was realized between October 2018 and March 2019, including terms like "Hand transplantation" AND "Composite tissue allotransplantation," "Hand transplantation" AND "Functional outcomes," "Hand transplantation" AND "Immunosuppression," "Hand prosthetics," "Hand Transplantation" AND "Ethics." There were included papers between 1995 and 2018, with English language, amputee human adults, systematic reviews, and clinical studies. Seventy-two papers were fully evaluated. There are technical aspects that influence the procedure like team coordination or surgical technique. It requires a long-life treatment, which has risks such as toxicity or infections. However, it allows the recovery of fine movements, and independence, to perform detailed tasks. The indications must be carefully considered, because some patients benefit from the use of prosthesis. CTA has become an option for amputees so it is important to do more research, to determine the benefits of this procedure. It is not considered a life-saving procedure, so there is an ethical debate because of the risks.

Salvage of a Near-Total Penile Amputation following Urinary Fistulization and Carbapenemase-Producing Klebsiella pneumoniae Infection with a Composite ALT Flap and Vascularized Fascia Lata.

Reconstruction of complex penile defects is always challenging, as some defects are not possible to reconstruct with skin or mucosa grafts, and even local flaps may be precluded in complex wounds. We present a case of a 63-year-old otherwise healthy man, who underwent transurethral resection of the prostate for benign prostatic hyperplasia. After the procedure, he developed panurethral necrosis with consequent stricture. Three urethroplasties for reconstruction of the bulbar and distal urethra using buccal mucosa grafts, a preputial flap, and penile skin were performed by urology team in different institutions, but serious urinary fistulization and carbapenemase-producing Klebsiella pneumoniae (KPC) infection translated in a chronic wound, urethra necrosis, and near-total penile amputation. A composite anterolateral thigh flap and vascularized fascia lata were used with success together with a perineal urethroplasty in different stages, improving the ischemic wound condition. The extended segment of fascia lata was used for Buck's fascia replacement and circumferential reinforcement to cover the erectile bodies of the penis. The postoperative period was uneventful and after 12 months, there were no signs of recurrence or wound dehiscence. He was able and easily adapted to void in a seated position through the perineal urethrostomy that was made. To the best of our knowledge, this procedure has not been reported previously as a salvage procedure in a fistulizated and KPC infected penis, but it may be considered to avoid penile amputation in chronic infected and intractable wounds.

The Apparent Activation Energy of a Novel Low-Calcium Silicate Hydraulic Binder.

In this work, the apparent activation energy (Ea) of a novel low-calcium binder was, for the first time, experimentally determined, using a calorimetric approach. Additionally, a correlation between the Ea, measured at the acceleration period with the C/S ratio of the hydration product is proposed. The Ea of the prepared pastes was determined through isothermal calorimetry tests by calculating the specific rate of reaction at different temperatures, using two different approaches. When comparing the Ea, at the acceleration period of this novel binder with the one published for alite and belite, we observed that its value is higher, which may be a result of a different hydration product formed with a distinct C/S ratio. Finally, to study the temperature effect on the compressive strength at early ages, a set of experiments with mortars was performed. The results showed that the longer the curing time at 35 °C, the higher the compressive strength after 2 days of hydration, which suggests a higher initial development of hydration products. This study also indicated that the novel binder has a higher sensitivity to temperature when compared with ordinary Portland cement (OPC).