Anderson Oliveira Lobo’s research while affiliated with Federal University of Piauí and other places

This article details the in situ preparation of composite scaffolds using polyurethane (PU) and HAp (hydroxyapatite), focusing on the unique properties of buriti oil (Mauritia flexuosa L.) applicable to tissue engineering. PU derived from vegetable oils, particularly buriti oil, has shown promise in bone tissue repair due to its rich bioactive compounds. Buriti oil is an excellent candidate for manufacturing these materials as it is an oil rich in bioactive compounds such as carotenoids, tocopherols, and fatty acids, which have antioxidant and anti-inflammatory properties. Furthermore, buriti oil has oleic acid as its principal fatty acid, which has been investigated as an excellent HAp dispersant. This research aimed to synthesize PU scaffolds from a polyol derived from buriti oil and incorporate HAp in different concentrations into the polymeric matrix through in situ polymerization. The chemical composition of the materials obtained, the distribution of hydroxyapatite particles in the polyurethane matrix, and the thermal stability were evaluated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), and thermogravimetry (TGA). In addition, to investigate biocompatibility, MTT tests (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium) were conducted using rat bone-marrow-derived mesenchymal stem cells (BMMSC). Characterizations confirm the formation of PU and the presence of HAp in the polymeric matrix, and the materials did not show cytotoxicity.

The development of new strategies to produce nanomaterials that can be used as personal protective equipment with antiviral activity and low toxicity is crucial. Electrospun ultrathin fibers have attracted considerable attention due to their potential for biomedical applications, including antiviral activity. Herein, we electrospun different grades of commercially available polyamide to produce ultrathin fibers and investigate their antiviral activity against SARS-CoV-2 Gamma lineage (P.1). We evaluated the morphology, chemical composition, and mechanical properties of the ultrathin fibers. We also investigated the in vitro cytotoxicity, hemolytic activity, and antiviral activity against SARS-CoV-2 Gamma lineage (P.1) of the developed ultrathin fibers. The ultrathin fibers had the following diameters and elastic moduli: (i) unmodified crude ultrathin polyamide (PAP) 0.59 μm and 3 MPa, (ii) polyamide Biotech (PAAM) 0.74 μm and 2.2 MPa, and (iii) Amni Virus-Bac OFF polyamide (PAVB) 0.69 μm and 1.06 MPa. The ultrathin PAP fibers showed increased antiviral activity compared to the other ultrathin fibers (PAAM and PAVB). None of the electrospun fibers showed cytotoxicity at the lowest concentration (12.5%). Additionally, hemolysis tests demonstrated a nonhemolytic profile for all fiber groups, reinforcing their biocompatibility and suitability for biomedical applications. The antiviral properties of the electrospun ultrathin PAP fibers, combined with their noncytotoxic and nonhemolytic characteristics, highlight their potential to be used as personal protection against SARS-CoV-2.

Background The 3D printing of macro- and mesoporous biomimetic grafts composed of polycaprolactone (PCL) infused with nanosized synthetic smectic clay is a promising innovation in biomaterials for bone tissue engineering (BTE). The main challenge lies in achieving a uniform distribution of nanoceramics across low to high concentrations within the polymer matrix while preserving mechanical properties and biological performance essential for successful osseointegration. Methods This study utilized 3D printing to fabricate PCL scaffolds enriched with nanosized synthetic smectic clay (LAP) to evaluate its effects on structural, chemical, thermal, mechanical, and degradative properties, with a focus on in vitro biological performance and non-toxicity. Scaffolds were created with varying proportions of PCL and LAP. Comprehensive characterization included scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), mechanical testing, swelling analysis, and degradation studies. Biological performance was assessed through MTT assays (cell viability), alkaline phosphatase activity, histological analysis, and Raman spectroscopy, highlighting the scaffolds’ biocompatibility and potential applications in regenerative medicine. Results The developed inks demonstrated excellent injectability, and the 3D-printed PCL/LAP scaffolds exhibited a microporous and rough structure, good structural fidelity, low degradability, thermal stability, and sufficient mechanical strength across all formulations. Intrinsic properties of the scaffolds revealed no cytotoxicity while enhancing bioactivity and promoting in vitro mineralization when cultured with mesenchymal stem cells in all analyzed groups. Notably, the high concentration of LAP within the PCL matrices did not induce in vitro cytotoxicity but rather stimulated in vitro mineralization and differentiation. Conclusion This study demonstrated the feasibility of 3D printing PCL/LAP scaffolds with high concentrations of nanoceramics. Both in vitro and in vivo assays validated the regenerative potential of these scaffolds, emphasizing their efficacy as a promising approach for developing advanced biomimetic grafts.

Alzheimer’s disease is the most prevalent form of dementia and is primarily characterized by the accumulation of β-amyloid and phosphorylated tau proteins in the brain, along with the degeneration of nerve cells, which leads to impairment of various cognitive functions. A significant biomarker of Alzheimer’s disease is the decreased level of soluble β-amyloid peptide (1–42) (Aβ 1-42 ) in cerebrospinal fluid (CSF), as pathology progresses when CSF-Aβ 1-42 levels drop below 192 pg mL ⁻¹ . In this study, we developed an amperometric immunosensor based on magnetic beads as the platform for constructing the immunosensor. Monoclonal antibodies are immobilized on the MBs, enabling selective detection of Aβ 1-42 . The detection antibody is conjugated with the enzyme horseradish peroxidase, which, in the presence of H 2 O 2 and hydroquinone, catalyzes the decomposition of H 2 O 2 and the oxidation of hydroquinone to p-quinone, generating an electric current measured at a potential of −200 mV (vs. the Ag pseudo-reference electrode) using screen-printed carbon electrodes. The amperometric sandwich-type immunosensor demonstrates a linear response in the concentration range of 10 to 10,000 pg mL ⁻¹ , with a detection limit of 7.4 pg mL ⁻¹ , exhibiting excellent selectivity against the assessed interferents. These findings suggest the potential application of this immunosensor in the early diagnosis of Alzheimer’s disease, offering a sensitive and specific tool for clinical analysis. Despite its high performance, further studies are required to validate its robustness and applicability in complex clinical samples.

Camomila (Matricaria Chamomila L.) é uma planta medicinal tradicional amplamente e usada para tratar diferentes tipos de doenças. Ela também possui propriedades anti-infecciosas, anti-inflamatórias, antioxidantes e antialérgicas. Laponita é um nanosilicato sintético que exibe um formato único e carga de superfície adequada para aplicações de administração de medicamentos. Pode ser útil como uma alternativa para liberar de oxigênio de forma sustentável e prolongada. O objetivo do estudo é mostrar a produção de hidrogéis à base de Laponita e Camomila (Matricaria Chamomila L) com liberação controlada de oxigênio para aplicação em feridas cutâneas infectadas. Para análise das estruturas das amostras utilizou-se a Microscopia Eletrônica de Varredura - MEV. A concentração de oxigênio foi medida usando um sensor óptico PRESENS (modelo OXY1 ST) por 6h e a medida analisada usando o software PreSens Measurement. As misturas com maior porcentagem de laponita (90% e 80%) requerem uma força maior para injeção, indicando que a laponita pode conferir maior viscosidade ou resistência à mistura. Por outro lado, as misturas com maior porcentagem de camomila (90% e 80%) parecem ser mais fáceis de injetar, especialmente em distâncias maiores, sugerindo que a camomila pode reduzir a resistência ao fluxo da mistura. O sensor óptico mediu a concentração de oxigênio e sua degradação também foram investigadas. A atividade bacteriana foi investigada através do tamanho do halo inibitório. A Laponita atuou como uma barreira eficiente ao oxigênio e mostrou atividade antimicrobiana. Os géis produzidos foram um candidato potencial para o tratamento de infecções e cicatrização de feridas cutâneas.

Purpose Tissue engineering aims to recreate natural cellular environments to facilitate tissue regeneration. Gelatin methacrylate (GelMA) is widely utilized for its biocompatibility, ability to support cell adhesion and proliferation, and adjustable mechanical characteristics. This study developed a GelMA and graphene bioink platform at concentrations of 1, 1.5, and 2 mg/mL to enhance scaffold properties for tissue engineering applications. Patients and Methods Graphene was incorporated into GelMA matrices to improve mechanical strength and electrical conductivity of the bioinks. The compressive strength and thermal stability of the resulting GelMA/graphene scaffolds were assessed through DSC analysis and mechanical testing. Cytotoxicity assays were conducted to determine cell survival rates. Cryoprinting at −30°C was employed to preserve scaffold structure and function. The chorioallantoic membrane (CAM) assay was used to evaluate biocompatibility and angiogenic potential. Results The integration of graphene significantly amplified the compressive strength and thermal stability of GelMA scaffolds. Cytotoxicity assays indicated robust cell survival rates of 90%, confirming the biocompatibility of the developed materials. Cryoprinting effectively preserved scaffold integrity and functionality. The CAM assay validated the biocompatibility and angiogenic potential, demonstrating substantial vascularization upon scaffold implantation onto chick embryo CAM. Conclusion Integrating graphene into GelMA hydrogels, coupled with low-temperature 3D printing, represents a potent strategy for enhancing scaffold fabrication. The resultant GelMA/graphene scaffolds exhibit superior mechanical properties, biocompatibility, and pro-vascularization capabilities, making them highly suitable for diverse tissue engineering and regenerative medicine applications.