Cytotoxicity Tests for Evaluating Medical Devices: An Alert for the Development of Biotechnology Health Products

The risks and damages related to the use of products, technologies and services of sanitary interest can be due to defects or manufacturing failures. Certain products already contain a certain degree of risk, which requires strict quality control in their production, distribution and use, as well as in the disposal of their waste in the environment. With continuous development in science and technology, medical devices must undergo intradermal irritation and testing for sensitization, cytotoxicity, and acute systemic toxicity. In health care, biotechnology aims to provide technology-based products or processes related to energy, food, and health, which are capable of stimulating new businesses, expanding exports, integrating the value chain and stimulating new demands for innovative products and processes, taking into account health policies. The present article was prepared by a bibliographical survey of the electronic databases PubMed, Lilacs, and Bireme. Cell culture testing can be successfully employed, as it is reproducible, rapid, sensitive, and financially accessible for performing in vitro toxicity testing. Thus, it has been possible to optimize the development phase of new products by decreasing animal use or even replacing them in certain tests. Some in vitro assays validated by the Organization for Economic Cooperation and Development in the area of health products have already replaced animal testing.

Adipose stromal/stem cells in regenerative medicine:Potentials and limitations

This article presents the stem and progenitor cells from subcutaneous adipose tissue,briefly comparing them with their bone marrow counterparts,and discussing their potential for use in regenerative medicine.Subcutaneous adipose tissue differs from other mesenchymal stromal/stem cells(MSCs)sources in that it contains a pre-adipocyte population that dwells in the adventitia of robust blood vessels.Pre-adipocytes are present both in the stromal-vascular fraction(SVF;freshly isolated cells)and in the adherent fraction of adipose stromal/stem cells(ASCs;in vitro expanded cells),and have an active role on the chronic inflammation environment established in obesity,likely due their monocyticmacrophage lineage identity.The SVF and ASCs have been explored in cell therapy protocols with relative success,given their paracrine and immunomodulatory effects.Importantly,the widely explored multipotentiality of ASCs has direct application in bone,cartilage and adipose tissue engineering.The aim of this editorial is to reinforce the peculiarities of the stem and progenitor cells from subcutaneous adipose tissue,revealing the spheroids as a recently described biotechnological tool for cell therapy and tissue engineering.Innovative cell culture techniques,in particular 3D scaffold-free cultures such as spheroids,are now available to increase the potential for regeneration and differentiation of mesenchymal lineages.Spheroids are being explored not only as a model for cell differentiation,but also as powerful 3D cell culture tools to maintain the stemness and expand the regenerative and differentiation capacities of mesenchymal cell lineages.

Cartilage and bone tissue engineering using adipose stromal/stem cells spheroids as building blocks

Scaffold-free techniques in the developmental tissue engineering area are designed to mimic in vivo embryonic processes with the aim of biofabricating,in vitro,tissues with more authentic properties.Cell clusters called spheroids are the basis for scaffold-free tissue engineering.In this review,we explore the use of spheroids from adult mesenchymal stem/stromal cells as a model in the developmental engineering area in order to mimic the developmental stages of cartilage and bone tissues.Spheroids from adult mesenchymal stromal/stem cells lineages recapitulate crucial events in bone and cartilage formation during embryogenesis,and are capable of spontaneously fusing to other spheroids,making them ideal building blocks for bone and cartilage tissue engineering.Here,we discuss data from ours and other labs on the use of adipose stromal/stem cell spheroids in chondrogenesis and osteogenesis in vitro.Overall,recent studies support the notion that spheroids are ideal"building blocks"for tissue engineering by“bottom-up”approaches,which are based on tissue assembly by advanced techniques such as three-dimensional bioprinting.Further studies on the cellular and molecular mechanisms that orchestrate spheroid fusion are now crucial to support continued development of bottom-up tissue engineering approaches such as three-dimensional bioprinting.

Non-Polar Chemical Constituents of Atemoya and Evaluation of the Cytotoxic and Antimicrobial Activity

This study aimed to identify the chemical composition of essential oil from fruits(EOAF)and the hexanic crude extract from aerial parts(At-Hex)of atemoya(Annona cherimola x Annona squamosa),a hybrid belonging to the Annonaceae family.Cytotoxic and antimicrobial activity was also evaluated.OEAF was obtained by hydrodistillation using a Clevenger apparatus,and their composition was analyzed by gas chromatography-mass spectrometry(GC-MS)analyses.Cytotoxicity was tested against human tumor cell lines HCT-116(colon carcinoma),SF-295(glioblastoma),OVCAR-8(ovarian carcinoma)and HL60(leukemia)using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide(MTT)assay,while antimicrobial activity was conducted by bioauthography method against eleven microorganisms strains.Twenty-four compounds were identified in the EOAF and twenty-nine in At-Hex.The monoterpenes linalool(25.70%),α-pinene(10.38%),β-pinene(9.12%),transocimene(7.43%),and the sesquiterpene bicyclogermacrene(12.58%)were the major constituents of EOAF,whereas the sesquiterpene spathulenol(13.91%)was the main compound of At-Hex.At-Hex showed a high cytotoxicity against SF-295(glioblastoma).These findings show an important chemotaxonomic contribution for the Annonaceae family,mainly for the Annona genus.Atemoya proved to be a promising source of substances with potential cytotoxic activity.

Basal repertoire of toxin-related transcripts in the zoanthid Protopalythoa variabilis(Cnidaria,Anthozoa)

OBJECTIVE To analyze the whole transcriptome of zoanthid Protopalythoa variabilis(P.variabilis),a cnidarian,and discover the potential toxic substances in P.variabilis.METHODS The P.variabilis RNA deep sequencing was performed using the HiSeq 2500 automatic sequencing platform.All the unigenes generated from the assembly process were functionally annotated based on the similarity with databases.The multiple alignments of translated toxin-related sequences were performed with Clustalw2,and amino acid identity and similarity highlighted by using BoxShade tool.Three different methods including ITASSER,PEP-FOLD and MODELLER were applied to predict tri-dimensional models of toxin-related polypeptides from translated transcript sequences of P.variabilis.The toxicity of one of the putative toxins,namely ShK/Aurelin-like peptide,was evaluated using zebrafish model.RESULTS A total of 67,549,914 pairs of quality-filtered,90-base-pair Illumina reads from an mRNA sample were obtained.The de novo assemblies yielded 276,526 contigs.The sequence comparison of 130,121 unigenes with entries in Toxin database showed that 1542 unigenes were potential peptide toxins at which 11 unigenes were related to Stichodactyla toxin(ShK)domain(Pfam ID:PF01549).ShK is a 35 residues peptide sequence that was firstly discovered from the sea anemone Stichodactyla helianthus.Here,we found out one ShK-like peptide that processed a relatively higher sequence similarity with known ShK(Uniprot ID:P29186)of Bunodosoma granuliferum(red warty sea anemone).The Protopalythoa Shk-like peptide was submitted to Probis server to detect probable binding site and found to match with a protein AURELIN(PDB id:2lg4,UniProt id:Q0MWV8)which possesses structural homology with previously identified antimicrobial peptides and K+-channel-blocking toxins.Our results showed that the ShK/Aurelin-like peptide was lethal to zebrafish embryos at concentrations above 30-μmol·L1,and could induce zebrafish locomotor deficit at 10μmol·L-1.CONCLUSION This study,for the first time,presented the whole transcriptome profile and a potential toxic peptide of P.variabilis.

Toxicological Study Employing Repeated Doses of Garcinielliptone FC, a Polyisoprenylated-Benzophenone Isolated from Seed of Platonia Insignis Mart

The major constituent from the hexane extract of the seeds ofP. insignis is GFC （garcinielliptone FC）. Doses of 25, 50 and 75 mg/kg of GFC were aseptically suspended in 0.05% Tween 80 dissolved in 0.9% saline （vehicle） and orally administered for 30, 90 and 120 consecutive days to adult Swiss mice. In this work, the repeated oral administration, in animals of both sexes, demonstrates that this compound is not able to induce mortality and/or behavioral changes in adult mice. In addition, body weight gain, feed intake and disposal of excreta were not altered by the administration of this compound with repeated doses. Furthermore, no differences in weight and macroscopic structure of the brain, liver, kidney, lung, heart and spleen between groups of male and female adult mice were observed after treatment. During the periods of treatment, GFC produced no significant changes on haematological and biochemical parameters in male and female mice treated with all doses used. The aim of this study was to investigate the toxicological potential of GFC through behavioral, hematological, biochemical and morphological parameters in animals in order to ensure the safe use ofPlatonia insignis in folk medicine.

Toxicity assessment of polyethylene microplastics in combination with a mix of emerging pollutants on Physalaemus cuvieri tadpoles

Studies in recent years have shown that aquatic pollution by microplastics(MPs)can be considered to pose additional stress to amphibian populations.However,our knowledge of how MPs affect amphibians is very rudimentary,and even more limited is our understanding of their effects in combination with other emerging pollutants.Thus,we aimed to evaluate the possible toxicity of polyethylene MPs(PE-MPs)(alone or in combination with a mix of pollutants)on the health of Physalaemus cuvieri tadpoles.After 30 days of exposure,multiple biomarkers were measured,including morphological,biometric,and developmental indices,behavioral parameters,mutagenicity,cytotoxicity,antioxidant and cholinesterase responses,as well as the uptake and accumulation of PE-MPs in animals.Based on the results,there was no significant change in any of the parameters measured in tadpoles exposed to treatments,but induced stress was observed in tadpoles exposed to PE-MPs combined with themixture of pollutants,reflecting significant changes in physiological and biochemical responses.Through principal component analysis(PCA)and integrated biomarker response(IBR)assessment,effects induced by pollutants in each test group were distinguished,confirming that the exposure of P.cuvieri tadpoles to the PE-MPs in combination with a mix of emerging pollutants induces an enhanced stress response,although the uptake and accumulation of PE-MPs in these animalswas reduced.Thus,our study provides newinsight into the danger to amphibians of MPs coexisting with other pollutants in aquatic environments.

Antibiofilm and immunomodulatory resorbable nanofibrous filing for dental pulp regenerative procedures

Multifunctional scaffolds with host defense peptides designed for regenerative endodontics are desirable nanobiotechnological tools for dentistry.Here,different scaffolds were tested for use during the pulp revascularization process,including poly(vinyl alcohol)-PVA hydrogels or resins,collagen hydrogels and poly(vinyl alcohol)PVA/Chitosan(PVA/CS)nanofibers.Based on time to degradation(21 days),nanofibers were chosen to be incorporated with ciprofloxacin and IDR-1002(each at 50 mg/g).Nanofibers containing ciprofloxacin and IDR-1002 had anti-biofilm activity against Enterococcus faecalis,Staphylococcus aureus and a multispecies oral biofilm,besides anti-inflammatory activities.The in vivo subcutaneous tissue response to tooth fragments filled with nanofibers demonstrated a pulp-like tissue formation,when compared to empty teeth fragments.Thus,we designed a strong antimicrobial,immunomodulatory and regenerative candidate for pulp revascularization and regeneration procedures.