Evaluation of polymersome permeability as a fundamental aspect towards the development of artificial cells and nanofactories.

Polymersomes are synthetic vesicles with potential use in healthcare, chemical transformations in confined environment (nanofactories), and in the construction of artificial cells and organelles. In this framework, one of the most important features of such supramolecular structures is the permeability behavior allowing for selective control of mass exchange between the inner and outer compartments. The use of biological and synthetic nanopores in this regard is the most common strategy to impart permeability nevertheless, this typically requires fairly complex strategies to enable porosity.

Development of Ac2-26 Mesoporous Microparticle System as a Potential Therapeutic Agent for Inflammatory Bowel Diseases.

Introduction: Inflammatory bowel diseases (IBDs) disrupt the intestinal epithelium, leading to severe chronic inflammation. Current therapies cause adverse effects and are expensive, invasive, and ineffective for most patients. Annexin A1 (AnxA1) is a pivotal endogenous anti-inflammatory and tissue repair protein in IBD.

Nucleic acid delivery to retinal cells using lipopeptides as a potential tool towards ocular gene therapies.

We evaluated the use of lipopeptides capable to bind to nucleic acids towards plasmid DNA (pDNA) delivery. The investigations were particularly focused on arising retinal pigment epithelial cells (ARPE-19) as motivated by the considerable number of ocular disorders linked to gene aberrations. The lipopeptides comprised the artificial oligoamino acid succinyl-tetraethylene pentamine (Stp) as well as incorporated lysines, histidines, cysteines, fatty acids, and tyrosine trimers.

Current overview of induced pluripotent stem cell-based blood-brain barrier-on-a-chip.

Background: Induced pluripotent stem cells (iPSCs) show great ability to differentiate into any tissue, making them attractive candidates for pathophysiological investigations. The rise of organ-on-a-chip technology in the past century has introduced a novel way to make cell cultures that more closely resemble their environments, both structural and functionally. The literature still lacks consensus on the best conditions to mimic the blood-brain barrier (BBB) for drug screening and other personalized therapies.

Balancing gene transfection and cytotoxicity of nucleic acid carriers with focus on ocular and hepatic disorders: evaluation of hydrophobic and hydrophilic polyethyleneimine derivatives.

Polyethyleneimine (PEI) derivatives substituted by lactose, succinic acid or alkyl domains were evaluated as nonviral gene delivery vectors towards balancing gene transfection and cytotoxicity. The investigations were focused on pDNA transfection into arising retinal pigment epithelia (ARPE-19) and human hepatocellular carcinoma (HepG2) cell lines. The first mentioned cell line was chosen as motivated by the non-negligible number of ocular disorders linked to gene aberrations, whereas the second one is a cell line overexpressing the asialoglycoprotein receptor (ASGP-R), which can bind to galactose residues.

How mesenchymal stem cell cotransplantation with hematopoietic stem cells can improve engraftment in animal models.

Background: Bone marrow transplantation (BMT) can be applied to both hematopoietic and nonhematopoietic diseases; nonetheless, it still comes with a number of challenges and limitations that contribute to treatment failure. Bearing this in mind, a possible way to increase the success rate of BMT would be cotransplantation of mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs) to improve the bone marrow niche and secrete molecules that enhance the hematopoietic engraftment.

Aim: To analyze HSC and MSC characteristics and their interactions through cotransplantation in murine models.

Gonococci resistant to current antimicrobial management standards: a new threat to global public health.

Gonorrhea is the second most common sexually transmitted bacterial infection on the planet and is caused by a Gram-negative cocco, . Currently, the preferred regimen for the management of this disease in Brazil is a combination of antimicrobials, in this case, ceftriaxone and azithromycin. However, over time, the gonococcus developed a decrease in susceptibility to the regimen used, which resulted in frank resistance to antimicrobials, progressively reducing the therapeutic options available.

Reduced cytotoxicity of nanomaterials driven by nano-bio interactions: Case study of single protein coronas enveloping polymersomes.

The protein adsorption onto poly(acrylic acid)-block-polystyrene (PAA-b-PS) polymersomes has been investigated with regard to structural features, thermodynamic aspects and biological consequences. The light scattering measurements revealed the formation of protein coronas enveloping the polymeric capsules regardless of the chemical nature of the biomacromolecules. The experiments were conducted by using lysozyme, immunoglobulin G - IgG and bovine serum albumin - BSA as model proteins due to their differences concerning size and residual surface charge at physiological pH.

Current Designs of Polymeric Platforms Towards the Delivery of Nucleic Acids Inside the Cells with Focus on Polyethylenimine.

Background: Gene delivery is a promising technology for treating diseases linked to abnormal gene expression. Since nucleic acids are the therapeutic entities in such approach, a transfecting vector is required because the macromolecules are not able to efficiently enter the cells by themselves. Viral vectors have been evidenced to be highly effective in this context; however, they suffer from fundamental drawbacks, such as the ability to stimulate immune responses.

Stem cell homing, tracking and therapeutic efficiency evaluation for stroke treatment using nanoparticles: A systematic review.

Background: Stroke is the second leading cause of death worldwide. There is a real need to develop treatment strategies for reducing neurological deficits in stroke survivors, and stem cell (SC) therapeutics appear to be a promising alternative for stroke therapy that can be used in combination with approved thrombolytic or thrombectomy approaches. However, the efficacy of SC therapy depends on the SC homing ability and engraftment into the injury site over a long period of time.

Outstanding protein-repellent feature of soft nanoparticles based on poly(N-(2-hydroxypropyl) methacrylamide) outer shells.

The influences of the hydrophilic chain length, morphology and chemical nature have been probed with regard to the adsorption of model proteins onto the surface of soft nanoparticles (crew-cut micelles and polymersomes). The investigations were based on assemblies manufactured from PEO-b-PLA (poly(ethylene oxide)-b-poly(lactic acid)), which is a well-established block copolymer platform towards the manufacturing of drug delivery vehicles, and PHPMA-b-PDPA (poly([N-(2-hydroxypropyl)]methacrylamide)-b-poly[2-(diisopropylamino)ethyl methacrylate]), which is pH-responsive and therefore potentially able to target damaged cells in slightly acid microenvironments. Besides, protein adsorption onto PHPMA-stabilized nanoparticles has been seldom explored up-to-date.

Polyglycidol-Stabilized Nanoparticles as a Promising Alternative to Nanoparticle PEGylation: Polymer Synthesis and Protein Fouling Considerations.

We herein demonstrate the outstanding protein-repelling characteristic of star-like micelles and polymersomes manufactured from amphiphilic block copolymers made by poly(butylene oxide) (PBO) hydrophobic segments and polyglycidol (PGL) hydrophilic outer shells. Although positively charged proteins (herein modeled by lysozyme) may adsorb onto the surface of micelles and polymersomes where the assemblies are stabilized by short PGL chains (degree of polymerization smaller than 15), the protein adsorption vanishes when the degree of polymerization of the hydrophilic segment (PGL) is higher than ∼20, regardless the morphology. This has been probed by using three different model proteins which are remarkably different concerning molecular weight, size, and zeta potential (bovine serum albumin (BSA), lysozyme, and immunoglobulin G (IgG)).

Triple-modal imaging of stem-cells labeled with multimodal nanoparticles, applied in a stroke model.

Background: Mesenchymal stem cells (MSCs) have been widely tested for their therapeutic efficacy in the ischemic brain and have been shown to provide several benefits. A major obstacle to the clinical translation of these therapies has been the inability to noninvasively monitor the best route, cell doses, and collateral effects while ensuring the survival and effective biological functioning of the transplanted stem cells. Technological advances in multimodal imaging have allowed monitoring of the biodistribution and viability of transplanted stem cells due to a combination of imaging technologies associated with multimodal nanoparticles (MNPs) using new labels and covers to achieve low toxicity and longtime residence in cells.

In vitro antifungal activity of Myracrodruon urundeuva Allemão against human vaginal Candida species.

Myracrodruon urundeuva is a plant native to Brazil, which is used by the indigenous population for the treatment of candidiasis. The aims of this study were to evaluate the antifungal activity of extract against human vaginal Candida species and evaluate the possible toxicological activities of M. urundeuva.

Scanning electron microscopy with energy dispersive spectroscopy and Raman and infrared spectroscopic study of tilleyite Ca5Si2O7(CO3)(2-)Y.

The mineral tilleyite-Y, a carbonate-silicate of calcium, has been studied by scanning electron microscopy with chemical analysis using energy dispersive spectroscopy (EDX) and Raman and infrared spectroscopy. Multiple carbonate stretching modes are observed and support the concept of non-equivalent carbonate units in the tilleyite structure. Multiple Raman and infrared bands in the OH stretching region are observed, proving the existence of water in different molecular environments in the structure of tilleyite.

SEM, EDS and vibrational spectroscopic study of dawsonite NaAl(CO3)(OH)2.

In this work we have studied the mineral dawsonite by using a combination of scanning electron microscopy with EDS and vibrational spectroscopy. Single crystals show an acicular habitus forming aggregates with a rosette shape. The chemical analysis shows a phase composed of C, Al, and Na.

SEM, EDX and vibrational spectroscopic study of the mineral tunisite NaCa2Al4(CO3)4Cl(OH)8.

The mineral tunisite has been studied by using a combination of scanning electron microscopy with energy dispersive X-ray fluorescence and vibrational spectroscopy. Chemical analysis shows the presence of Na, Ca, Al and Cl. SEM shows a pure single phase.

A vibrational spectroscopic study of tengerite-(Y) Y2(CO3)3 2-3H2O.

The mineral tengerite-(Y) has been studied by vibrational spectroscopy. Multiple carbonate stretching modes are observed and support the concept of non-equivalent carbonate units in the tengerite-(Y) structure. Intense sharp bands at 464, 479 and 508 cm(-1) are assigned to YO stretching modes.