Reduced graphene oxide-reinforced tricalcium phosphate/gelatin/chitosan light-responsive scaffolds for application in bone regeneration.

Bone is a mineralized tissue with the intrinsic capacity for constant remodeling. Rapid prototyping techniques, using biomaterials that mimic the bone native matrix, have been used to develop osteoinductive and osteogenic personalized 3D structures, which can be further combined with drug delivery and phototherapy. Herein, a Fab@Home 3D Plotter printer was used to promote the layer-by-layer deposition of a composite mixture of gelatin, chitosan, tricalcium phosphate, and reduced graphene oxide (rGO). The phototherapeutic potential of the new NIR-responsive 3D_rGO scaffolds was assessed by comparing scaffolds with different rGO concentrations (1, 2, and 4 mg/mL). The data obtained show that the rGO incorporation confers to the scaffolds the capacity to interact with NIR light and induce a hyperthermy effect, with a maximum temperature increase of 16.7 °C after under NIR irradiation (10 min). Also, the increase in the rGO content improved the hydrophilicity and mechanical resistance of the scaffolds, particularly in the 3D_rGO4. Furthermore, the rGO could confer an NIR-triggered antibacterial effect to the 3D scaffolds, without compromising the osteoblasts' proliferation and viability. In general, the obtained data support the development of 3D_rGO for being applied as temporary scaffolds supporting the new bone tissue formation and avoiding the establishment of bacterial infections.

Lignin-enriched tricalcium phosphate/sodium alginate 3D scaffolds for application in bone tissue regeneration.

The bone is a connective, vascularized, and mineralized tissue that confers protection to organs, and participates in the support and locomotion of the human body, maintenance of homeostasis, as well as in hematopoiesis. However, throughout the lifetime, bone defects may arise due to traumas (mechanical fractures), diseases, and/or aging, which when too extensive compromise the ability of the bone to self-regenerate. To surpass such clinical situation, different therapeutic approaches have been pursued. Rapid prototyping techniques using composite materials (consisting of ceramics and polymers) have been used to produce customized 3D structures with osteoinductive and osteoconductive properties. In order to reinforce the mechanical and osteogenic properties of these 3D structures, herein, a new 3D scaffold was produced through the layer-by-layer deposition of a tricalcium phosphate (TCP), sodium alginate (SA), and lignin (LG) mixture using the Fab@Home 3D-Plotter. Three different TCP/LG/SA formulations, LG/SA ratio 1:3, 1:2, or 1:1, were produced and subsequently evaluated to determine their suitability for bone regeneration. The physicochemical assays demonstrated that the LG inclusion improved the mechanical resistance of the scaffolds, particularly in the 1:2 ratio, since a 15 % increase in the mechanical strength was observed. Moreover, all TCP/LG/SA formulations showed an enhanced wettability and maintained their capacity to promote the osteoblasts' adhesion and proliferation as well as their bioactivity (formation of hydroxyapatite crystals). Such results support the LG inclusion and application in the development of 3D scaffolds aimed for bone regeneration.

In Vivo bone tissue induction by freeze-dried collagen-nanohydroxyapatite matrix loaded with BMP2/NS1 mRNAs lipopolyplexes.

Messenger RNA (mRNA) activated matrices (RAMs) are interesting to orchestrate tissue and organ regeneration due to the in-situ and sustained production of functional proteins. However, the immunogenicity of in vitro transcribed mRNA and the paucity of proper in vivo mRNA delivery vector need to be overcome to exert the therapeutic potential of RAM. We developed a dual mRNAs system for in vitro osteogenesis by co-delivering NS1 mRNA with BMP2 mRNA to inhibit RNA sensors and enhance BMP-2 expression. Next, we evaluated a lipopolyplex (LPR) formulation platform for in vivo mRNA delivery and adapted the LPRs for RAM preparation. The LPR formulated BMP2/NS1 mRNAs were incorporated into an optimized collagen-nanohydroxyapatite scaffold and freeze-dried to prepare ready-to-use RAMs. The loaded BMP2/NS1 mRNAs lipopolyplexes maintained their spherical morphology in the RAM, thanks to the core-shell structure of LPR. The mRNAs release from RAMs lasted for 16 days resulting in an enhanced prolonged transgene expression period compared to direct cell transfection. Once subcutaneously implanted in mice, the BMP2/NS1 mRNAs LPRs containing RAMs (RAM-BMP2/NS1) induced significant new bone tissue than those without NS1 mRNA, eight weeks post implantation. Overall, our results demonstrate that the BMP2/NS1 dual mRNAs system is suitable for osteogenic engagement, and the freeze-dried RAM-BMP2/NS1 could be promising off-the-shelf products for clinical orthopedic practice.

Injectable in situ forming thermo-responsive graphene based hydrogels for cancer chemo-photothermal therapy and NIR light-enhanced antibacterial applications.

Functionalized graphene oxide (GO) and reduced GO (rGO) based nanomaterials hold a great potential for cancer photothermal therapy. However, their systemic administration has been associated with an accelerated blood clearance and/or with suboptimal tumor uptake. To address these limitations, the local delivery of GO/rGO to the tumor site by 3D matrices arises as a promising strategy. In this work, injectable chitosan-agarose in situ forming thermo-responsive hydrogels incorporating GO (thermogel-GO) or rGO (thermogel-rGO) were prepared for the first time. The hydrogels displayed suitable injectability and gelation time, as well as good physicochemical properties and cytocompatibility. When irradiated with near infrared (NIR) light, the thermogel-rGO produced a 3.8-times higher temperature increase than thermogel-GO, thus decreasing breast cancer cells' viability to 60%. By incorporating an optimized molar ratio of the Doxorubicin:Ibuprofen combination on thermogel-rGO, this formulation mediated a chemo-photothermal effect that further diminished cancer cells' viability to 34%. In addition, the hydrogels' antibacterial activity was further enhanced upon NIR laser irradiation, which is an important feature considering the possible risk of infection at the site of administration. Overall, thermogel-rGO is a promising injectable in situ forming hydrogel for combinatorial chemo-photothermal therapy of breast cancer cells and NIR light enhanced antibacterial applications.

Hyaluronic acid-Based wound dressings: A review.

Hyaluronic acid (HA), a non-sulfated glycosaminoglycan (GAG), is a major component of skin extracellular matrix (ECM) and it is involved in the inflammatory response, angiogenesis, and tissue regeneration process. Due to the intrinsic properties of HA (such as biocompatibility, biodegradability and hydrophilic character), it has been used to produce different wound dressings, namely sponges, films, hydrogels, and electrospun membranes. Herein, an overview of the different HA-based wound dressings that have been produced so far is provided as well as the future directions regarding the strategies aimed to improve the mechanical stability of HA-based wound dressings, along with the incorporation of biomolecules intended to ameliorate their biological performance during the healing process.

Substernal Goiter: a case to remember.

Goiter is a localized or generalized thyroid hypertrophy. It can remain within the cervical region or grow down until it invades the mediastinum. The signs and symptoms depend on the size and location of the goiter. Although drugs and radioactive iodine are often used to treat thyroid disease, the presence of symptomatic substernal goiter is a clear indication for surgery. Death or postoperative complications rarely occur. We present a case of a 71-year-old man with recurrent thyroid pathology in the form of substernal goiter and hyperthyroidism even after partial thyroidectomy. The importance of this relates to the clinical evolution, volume, and location of the goiter as well as the surgical and pharmacological approach.

Substernal Goiter: a case to remember

SUMMARY Goiter is a localized or generalized thyroid hypertrophy. It can remain within the cervical region or grow down until it invades the mediastinum. The signs and symptoms depend on the size and location of the goiter. Although drugs and radioactive iodine are often used to treat thyroid disease, the presence of symptomatic substernal goiter is a clear indication for surgery. Death or postoperative complications rarely occur. We present a case of a 71-year-old man with recurrent thyroid pathology in the form of substernal goiter and hyperthyroidism even after partial thyroidectomy. The importance of this relates to the clinical evolution, volume, and location of the goiter as well as the surgical and pharmacological approach.

RESUMO O bócio é a hipertrofia da glândula tiroide localizada ou generalizada. Esta pode localizar-se na região cervical ou crescer através do mediastino. Os sinais e sintomas dependem do tamanho e da localização do bócio. Embora os fármacos e o iodo radioativo sejam frequentemente usados para tratar doenças tireoidianas, a presença do bócio subesternal sintomático é uma clara indicação para a cirurgia. A morte ou complicações pós-operatórias são raras. Apresentamos o caso de um homem de 71 anos com recorrência de patologia tireoidiana sob a forma de bócio subesternal e hipertireoidismo após tireoidectomia parcial. A importância desse caso relaciona-se com a evolução clínica, o volume e a localização do bócio e a abordagem cirúrgica e farmacológica desse tipo de patologia.

Development of a poly(vinyl alcohol)/lysine electrospun membrane-based drug delivery system for improved skin regeneration.

Nanofiber-based wound dressings are currently being explored as delivery systems of different biomolecules for avoiding skin infections as well as improve/accelerate the healing process. In the present work, a nanofibrous membrane composed of poly(vinyl alcohol) (PVA) and lysine (Lys) was produced by using the electrospinning technique. Further, anti-inflammatory (ibuprofen (IBP)) and antibacterial (lavender oil (LO)) agents were incorporated within the electrospun membrane through blend electrospinning and surface physical adsorption methods, respectively. The obtained results demonstrated that the PVA_Lys electrospun membranes incorporating IBP or LO displayed the suitable morphological, mechanical and biological properties for enhancing the wound healing process. Moreover, the controlled and sustained release profile attained for IBP was appropriate for the duration of the wound healing inflammatory phase, whereas the initial burst release of LO is crucial to prevent wound bacterial contamination. Indeed, the PVA_Lys_LO electrospun membranes were able to mediate a strong antibacterial activity against both S. aureus and P. aeruginosa, without compromising human fibroblasts viability. Overall, the gathered data emphasizes the potential of the PVA_Lys electrospun membranes-based drug delivery systems to be used as wound dressings.

Ocular Melanoma Presenting as Masquerade Syndrome.

A masquerade syndrome is an ophthalmological entity where a neoplasm mimics an inflammatory condition. Ocular melanoma (chiefly uveal) may present with symptoms suggestive of intraocular inflammation such as endogenous endophthalmitis. Ocular melanoma is most commonly found in middle-aged and older caucasian patients. One-third of all uveal melanoma cases present asymptomatically. Early diagnosis facilitates treatment before ocular melanoma reaches metastatic stage IV. Current therapy options for stage IV patients are palliative care and clinical trial participation. LEARNING POINTS: Masquerade syndrome and intraocular haemorrhage can hide a neoplastic aetiology.A biopsy should be carried out for correct diagnosis if intraocular haemorrhage is present and a neoplastic pathology is suspected.A multidisciplinary approach should be adopted to enhance the quality of life of patients with metastatic ocular melanoma.

Production and characterization of a novel asymmetric 3D printed construct aimed for skin tissue regeneration.

Skin is a complex organ that act as the first protective barrier against any external threat. After an injury occurs, its structure and functions must be re-established as soon as possible. Among different available skin substitutes (epidermal, dermal and dermo-epidermal), none of them is fully capable of reproducing/re-establishing all the features and functions of native skin. Herein, a three-dimensional skin asymmetric construct (3D_SAC) was produced using electrospinning and 3D bioprinting techniques. A poly(caprolactone) and silk sericin blend was electrospun to produce a top layer aimed to mimic the epidermis features, i.e. to provide a protective barrier against dehydration and hazard agents. In turn, the dermis like layer was formed by printing layer-by-layer a chitosan/sodium alginate hydrogel. The results obtained in the in vitro assays revealed that the 3D_SAC display a morphology, porosity, mechanical properties, wettability, antimicrobial activity and a cytotoxic profile that grants their application as a skin substitute during the healing process.

Eosinophilic fasciitis: an atypical presentation of a rare disease.

Eosinophilic fasciitis, or Shulman's disease, is a rare disease of unknown etiology. It is characterized by peripheral eosinophilia, hypergammaglobulinemia, and high erythrocyte sedimentation rate. The diagnosis is confirmed by a deep biopsy of the skin. The first line of treatment is corticotherapy. We present a rare case of eosinophilic fasciitis in a 27-year-old woman with an atypical presentation with symmetrical peripheral edema and a Groove sign. The patient responded well to treatment with corticosteroids at high doses and, in this context, was associated with hydroxychloroquine and azathioprine. After two and a half years, peripheral eosinophilia had increased, and more of her skin had hardened. At that time, the therapy was modified to include corticoids, methotrexate, and penicillamine. It is of great importance to publicize these cases that allow us to gather experience and better treat our patients.

Easy resolution of severe obstructive kidney injury.

Chronic constipation is a common diagnosis with a high prevalence in the elderly. Constipation affects the quality of life of sick individuals, bringing several clinical complications.

Photocrosslinkable Nanofibrous Asymmetric Membrane Designed for Wound Dressing.

Recently, the biomedical scientists who are working in the skin regeneration area have proposed asymmetric membranes as ideal wound dressings, since they are able to reproduce both layers of skin and improve the healing process as well as make it less painful. Herein, an electrospinning technique was used to produce new asymmetric membranes. The protective layer was composed of a blending solution between polycaprolactone and polylactic acid, whereas the underlying layer was comprised of methacrylated gelatin and chitosan. The chemical/physical properties, the in vitro hemo- and biocompatibility of the nanofibrous membranes were evaluated. The results obtained reveal that the produced membranes exhibited a wettability able to provide a moist environment at wound site. Moreover, the membranes' hemocompatibility and fibroblast cell adhesion, spreading and proliferation at the surface of the membranes were also noticed in the in vitro assays. Such results highlight the suitability of these asymmetric membranes for wound dressing applications.

An overview of electrospun membranes loaded with bioactive molecules for improving the wound healing process.

Nowadays, despite the intensive research performed in the area of skin tissue engineering, the treatment of skin lesions remains a big challenge for healthcare professionals. In fact, none of the wound dressings currently used in the clinic is capable of re-establishing all the native features of skin. An ideal wound dressing must confer protection to the wound from external microorganisms, chemical, and physical aggressions, as well as promote the healing process by stimulating the cell adhesion, differentiation, and proliferation. In recent years different types of wound dressings (such as films, hydrocolloids, hydrogels, micro/nano fibers) have been developed. Among them, electrospun nanofibrous membranes due to their intrinsic properties like high surface area-to-volume ratio, porosity and structural similarity with the skin extracellular matrix have been regarded as highly promising for wound dressings applications. Additionally, the nanofibers available in these membranes can act as drug delivery systems, which prompted the incorporation of biomolecules within their structure to prevent skin infections as well as improve the healing process. In this review, examples of different bioactive molecules that have been loaded on polymeric nanofibers are presented, highlighting the antibacterial biomolecules (e.g. antibiotics, silver nanoparticles and natural extracts-derived products) and the molecules capable of enhancing the healing process (e.g. growth factors, vitamins, and anti-inflammatory molecules).

Eosinophilic fasciitis: an atypical presentation of a rare disease

SUMMARY Eosinophilic fasciitis, or Shulman's disease, is a rare disease of unknown etiology. It is characterized by peripheral eosinophilia, hypergammaglobulinemia, and high erythrocyte sedimentation rate. The diagnosis is confirmed by a deep biopsy of the skin. The first line of treatment is corticotherapy. We present a rare case of eosinophilic fasciitis in a 27-year-old woman with an atypical presentation with symmetrical peripheral edema and a Groove sign. The patient responded well to treatment with corticosteroids at high doses and, in this context, was associated with hydroxychloroquine and azathioprine. After two and a half years, peripheral eosinophilia had increased, and more of her skin had hardened. At that time, the therapy was modified to include corticoids, methotrexate, and penicillamine. It is of great importance to publicize these cases that allow us to gather experience and better treat our patients.

RESUMO A fasciite eosinofílica ou doença de Shulman é uma doença rara de etiologia desconhecida. É caracterizada por eosinofilia periférica, hipergamaglobulinemia e velocidade de sedimentação eritrocitária elevada. O diagnóstico é confirmado por biópsia profunda da pele. O tratamento de primeira linha é a corticoterapia. Apresentamos um caso raro de fasciite eosinofílica numa mulher de 27 anos com uma apresentação atípica com edema periférico simétrico e sinal de Groove. A paciente respondeu bem ao tratamento com corticoides, mas em doses elevadas, e, nesse contexto, associou-se hidroxicloroquina e azatioprina. Ao fim de dois anos e meio verificou-se aumento de eosinofilia e novamente pele mais endurecida. Nessa altura alterou-se a terapêutica para corticoides, metrotexato e penicilamina. É de grande importância a divulgação desses casos que nos permitem reunir experiência e assim melhor tratar os nossos doentes.

Easy resolution of severe obstructive kidney injury

SUMMARY Chronic constipation is a common diagnosis with a high prevalence in the elderly. Constipation affects the quality of life of sick individuals, bringing several clinical complications.

RESUMO A obstipação crônica é um diagnóstico com alta prevalência comum em idosos. A constipação afeta a qualidade de vida das pessoas doentes, carregando muitas complicações clínicas.

Terlipressin-related Ischaemic Necrosis of the Skin: A Rare Complication.

Terlipressin is used for the treatment of bleeding oesophageal varices and hepatorenal syndrome in patients with cirrhosis. Adverse effects are usually minimal. However, potentially serious side effects such as skin necrosis involving the extremities, scrotum, trunk and abdominal skin can rarely occur. Our patient had greater skin involvement than other described cases. We present the case of a patient with extensive skin necrosis, unrelated to the infusion site, in the lower and upper limbs, scrotum and abdomen after the use of terlipressin. Skin necrosis secondary to terlipressin is a rare complication and early identification is essential so the drug can be immediately suspended. LEARNING POINTS: Skin necrosis secondary to terlipressin is a rare complication.Early identification is essential so the drug can be immediately suspended.Death is not directly related to the skin necrosis but to the secondary complications of advanced liver disease.