BACKGROUND:Protein subunit vaccines have a strong track record of efficacy and safety and have been widely applied for prevention of a variety of infectious diseases. The impacts of post-translational modifications of vaccine antigens are often overlooked, despite the fact that they can vary significantly depending on the expression hosts (e.g., bacteria, yeast, plant, insect or mammalian cells) and the culture conditions used for their manufacturing. METHODS:Using SARS-CoV-2 spike trimers as model antigens, we sought to evaluate the immunological impact of modulating their state of glycosylation. Spike proteins rich in complex-type (CT), high-mannose (HM) or paucimannose (PM) N-linked glycans were produced using Chinese Hamster Ovary (CHO) cells (cultured with or without the mannosidase inhibitor kifunensine) or insect cells. RESULTS:Here we show that when these antigens are adjuvanted with liposomes composed of sulfated lactosyl archaeol (SLA), all glycoforms are highly immunogenic and induce abundant spike-specific serum IgG and IFN-γ producing T-cells within female C57BL/6 mice. The spike antigen with CT glycans induces a significantly more potent neutralizing immune response, which directly correlates to more abundant receptor binding domain (RBD)-specific IgG when comparing to the antigen with HM glycans. This observation remains true whether the spike is resistin- or T4 foldon-trimerized, indicating that the glycosylation effect is not trimerization domain-specific. Spike with PM glycans induces remarkably low titers of neutralizing antibodies and RBD-specific IgG. CONCLUSIONS:The results highlight the significant impacts of a vaccine's antigen glycosylation profile in directing the immune response, which should be an important consideration for designing efficient protein-based vaccines.
The insect cell-baculovirus expression vector system (IC-BEVS) has been an asset to produce biologics for over 30 years. With the current trend in biotechnology shifting toward process intensification and integration, developing intensified processes such as continuous production is crucial to hold this platform as a suitable alternative to others. However, the implementation of continuous production has been hindered by the lytic nature of this expression system and the process-detrimental virus passage effect. In this study, we implemented a multi-stage bioreactor setup for continuous production of influenza hemagglutinin-displaying virus-like particles (HA-VLPs) using IC-BEVS. A setup consisting of one Cell Growth Bioreactor simultaneously feeding non-infected insect cells to three parallel Production Bioreactors operated at different residence times (RT) (18, 36, and 54 h) was implemented; Production Bioreactors were continuously harvested. Two insect cell lines (neutral pH-adapted High Five and Sf9) and two recombinant baculovirus (rBAC) constructs (one that originates from a bacmid, rBACbacmid, and another of non-bacteria origin, rBACflashbac) were tested. Combining rBACflashbac with Sf9 cells was the most efficient approach, allowing consistent HA-VLPs titers (34 ± 14 HA titer/mL) and rBAC titers (108-109 pfu/mL) throughout the period of continuous operation (20 days). Cell growth kinetics and viability varied across RT, and higher RT was associated with increased expression of HA-VLPs, independent of the cell line and rBAC used; RT of 54 h allowed to maximize titers. The presence of particles resembling HA-VLPs was confirmed by transmission electron microscopy throughout the continuous operation. This work showcases the implementation of a process for continuous production of a promising class of biotherapeutics (i.e., VLPs), and paves the way for establishing continuous, integrated setups using the IC-BEVS expression system.
As lesões odontogênicas originam-se de tecidos epiteliais relacionados ao desenvolvimento do aparelho odontogênico ou de restos de células presas durante a organogênese. Pode acometer diferentes regiões, tecidos da cavidade bucal e estruturas anatômicas nobres importantes que abrangem os maxilares e a mandíbula. Os cistos odontogênicos são lesões patológicas que se formam na cavidade bucal podendo conter líquido, semifluido ou gás. Diante disso, esta revisão de literatura tem como objetivo apresentar os avanços quanto ao diagnóstico e manejo de lesões císticas e tumorais benignas da mandíbula. Os cistos odontogênicos são classificados como cistos de desenvolvimento, inflamatórios e não odontogênicos, geralmente são assintomáticos e crescem lentamente. Podem causar deslocamento de estruturas circundantes, expansão, má oclusão e assimetria facial. Os tumores odontogênicos podem ser de origem benigna ou maligna, resultante da multiplicação de células. O diagnóstico e tratamento das lesões císticas são importantes pois essas lesões podem gerar complicações de deformação óssea, perda de dentes e evoluir para tumores.Assim, o diagnóstico de lesões císticas na mandíbula pode ser obtido por exames de ortopantomografia, tomografia computadorizada e tomografia computadorizada de feixe cônico. Dentre os tratamentos mais indicados para lesões císticas, têm-se a descompressão, marsupialização, enucleação e ressecção óssea, ou até mesmo uma combinação de todos esses tratamentos, contudo, cada técnica apresenta suas vantagens e desvantagens. Portanto, é de suma importância integrar tecnologias avançadas no diagnóstico e tratamento de lesões odontogênicas visando o bem-estar e recuperação do paciente.
Adaptive laboratory evolution (ALE) is a powerful tool for enhancing the fitness of cell lines in specific applications, including recombinant protein production. Through adaptation to nonstandard culture conditions, cells can develop specific traits that make them high producers. Despite being widely used for microorganisms and, to lesser extent, for mammalian cells, ALE has been poorly leveraged for insect cells. Here, we describe a method for adapting insect High Five and Sf9 cells to nonstandard culture conditions via an ALE approach. Aiming to demonstrate the potential of ALE to improve productivity of insect cells, two case studies are demonstrated. In the first, we adapted insect High Five cells from their standard pH (6.2) to neutral pH (7.0); this adaptation allowed to improve production of influenza virus-like particles (VLPs) by threefold, using the transient baculovirus expression vector system. In the second, we adapted insect Sf9 cells from their standard culture temperature (27 °C) to hypothermic growth (22 °C); this adaptation allowed to improve production of influenza VLPs by sixfold, using stable cell lines. These examples demonstrate the potential of ALE for enhancing productivity within distinct insect cell hosts and expression systems by manipulating different culture conditions.
Pyruvate:quinone oxidoreductases (PQOs) catalyse the oxidative decarboxylation of pyruvate to acetate and concomitant reduction of quinone to quinol with the release of CO2. They are thiamine pyrophosphate (TPP) and flavin-adenine dinucleotide (FAD) containing enzymes, which interact with the membrane in a monotopic way. PQOs are considered as part of alternatives to most recognized pyruvate catabolizing pathways, and little is known about their taxonomic distribution and structural/functional relationship. In this bioinformatics work we tackled these gaps in PQO knowledge. We used the KEGG database to identify PQO coding genes, performed a multiple sequence analysis which allowed us to study the amino acid conservation on these enzymes, and looked at their possible cellular function. We observed that PQOS are enzymes exclusively present in prokaryotes with most of the sequences identified in bacteria. Regarding the amino acid sequence conservation, we found that 75 amino acid residues (out of 570, on average) have a conservation over 90 %, and that the most conserved regions in the protein are observed around the TPP and FAD binding sites. We systematized the presence of conserved features involved in Mg2+, TPP and FAD binding, as well as residues directly linked to the catalytic mechanism. We also established the presence of a new motif named "HEH lock", possibly involved in the dimerization process. The results here obtained for the PQO protein family contribute to a better understanding of the biochemistry of these respiratory enzymes.
Adeno-associated viruses (AAVs) demand for clinical trials and approved therapeutic applications is increasing due to this vector’s overall success and potential. The high doses associated with administration strategies challenges bioprocess engineers to develop more efficient technologies and innovative strategies capable of increasing volumetric productivity. In this study, alternating tangential flow (ATF) and Tangential Flow Depth filtration (TFDF) techniques were compared as to their potential for 1) implementing a high-cell-density perfusion process to produce AAV8 using mammalian HEK293 cells and transient transfection, and 2) integrating AAV harvest and clarification units into a single step. On the first topic, the results obtained demonstrate that AAV expression improves with a medium exchange strategy. This was evidenced firstly in the small-scale perfusion-mocking study and later verified in the 2 L bioreactor operated in perfusion mode. Fine-tuning the shear rate in ATF and TFDF proved instrumental in maintaining high cell viabilities and, most importantly, enhancing AAV-specific titers (7.6 × 10 4 VG/cell), i.e., up to 4-fold compared to non-optimized perfusion cultures and 2-fold compared with batch operation mode. Regarding the second objective, TFDF enabled the highest recovery yields during perfusion-based continuous harvest of extracellular virus and lysate clarification. This study demonstrates that ATF and TFDF techniques have the potential to support the production and continuous harvest of AAV, and enable an integrated clarification procedure, contributing to the simplification of operations and improving manufacturing efficiency.
The malaria asexual blood-stage antigen PfRipr and its most immunogenic fragment PfRipr5 have recently risen as promising vaccine candidates against this infectious disease. Continued development of high-yielding, scalable production platforms is essential to advance the malaria vaccine research. Insect cells have supplied the production of numerous vaccine antigens in a fast and cost-effective manner; improving this platform further could prove key to its wider use. In this study, insect ( Sf 9 and High Five) and human (HEK293) cell hosts as well as process-optimizing strategies (new baculovirus construct designs and a culture temperature shift to hypothermic conditions) were employed to improve the production of the malaria asexual blood-stage vaccine candidate PfRipr5. Protein expression was maximized using High Five cells at CCI of 2 × 10 6 cell/mL and MOI of 0.1 pfu/cell (production yield = 0.49 mg/ml), with high-purity PfRipr5 binding to a conformational anti-PfRipr monoclonal antibody known to hold GIA activity and parasite PfRipr staining capacity. Further improvements in the PfRipr5 expression were achieved by designing novel expression vector sequences and performing a culture temperature shift to hypothermic culture conditions. Addition of one alanine (A) amino acid residue adjacent to the signal peptide cleavage site and a glycine-serine linker (GGSGG) between the PfRipr5 sequence and the purification tag (His 6 ) induced a 2.2-fold increase in the expression of secreted PfRipr5 over using the expression vector with none of these additions. Performing a culture temperature shift from the standard 27–22°C at the time of infection improved the PfRipr5 expression by up to 1.7 fold. Notably, a synergistic effect was attained when combining both strategies, enabling to increase production yield post-purification by 5.2 fold, with similar protein quality (i.e., purity and binding to anti-PfRipr monoclonal antibody). This work highlights the potential of insect cells to produce the PfRipr5 malaria vaccine candidate and the importance of optimizing the expression vector and culture conditions to boost the expression of secreted proteins.
Protein production processes based on stable insect cell lines require intensification to be competitive with the insect cell-baculovirus expression vector system (IC-BEVS). High cell density (HCD) cultures operate continuously, capable of maintaining specific production rates for extended periods of time which may lead to significant improvements in production yields. However, setting up such processes is challenging (e.g., selection of cell retention device and optimization of dilution rate), often demanding the manipulation of large volumes of culture medium with associated high cost. In this study, we developed a process for continuous production of Gag virus–like particles (VLP) pseudotyped with a model membrane protein (influenza hemagglutinin, HA) at HCD using stable insect cells adapted to low culture temperature. The impact of the cell retention device (ATF vs. TFF) and cell-specific perfusion rate (CSPR) on cell growth and protein expression kinetics was evaluated. Continuous production of Gag-HA VLPs was possible using both retention devices and CSPR of 0.04 nL/cell.d; TFF induces higher cell lysis when compared to ATF at later stages of the process (kD = 0.009 vs. 0.005 h−1, for TFF and ATF, respectively). Reducing CSPR to 0.01–0.02 nL/cell.d using ATF had a negligible impact on specific production rates (rHA = 72–68 titer/109 cell.h and rp24 = 12–11 pg/106 cell.h in all CSPR) and on particle morphology (round-shaped structures displaying HA spikes on their surface) and size distribution profile (peaks at approximately 100 nm). Notably, at these CSPRs, the amount of p24 or HA formed per volume of culture medium consumed per unit of process time increases by up to 3-fold when compared to batch and perfusion operation modes. Overall, this work demonstrates the potential of manipulating CSPRs to intensify the continuous production of Gag-HA VLPs at HCD using stable insect cells to make them an attractive alternative platform to IC-BEVS.
A 51- year- old female, fish canning industry worker, with a personal history of arterial hypertension, dyslipidemia, and peripheral venous in-sufficiency, presented with a 3 month history of painful erythematous nodules with a scaly surface located bilaterally on the posterior side of her legs (Figure 1). No other concomitant symptoms and relevant ep-idemiological or family medical history were present. She reported no previous infections, trauma, or new medications. On physical examination, she had multiple tender nodules with perilesional erythema on the posterior- medial aspect of both legs. Laboratory studies revealed:
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) homotrimeric spike (S) protein is responsible for mediating host cell entry by binding to the angiotensin-converting enzyme 2 (ACE2) receptor, thus being a key viral antigen to target in a coronavirus disease 19 (COVID-19) vaccine. Despite the availability of COVID-19 vaccines, low vaccine coverage as well as unvaccinated and immune compromised subjects are contributing to the emergence of SARS-CoV-2 variants of concern. Therefore, continued development of novel and/or updated vaccines is essential for protecting against such new variants. In this study, we developed a scalable bioprocess using the insect cells-baculovirus expression vector system (IC-BEVS) to produce high-quality S protein, stabilized in its pre-fusion conformation, for inclusion in a virosome-based COVID-19 vaccine candidate. By exploring different bioprocess engineering strategies (i.e., signal peptides, baculovirus transfer vectors, cell lines, infection strategies and formulation buffers), we were able to obtain ~4 mg/L of purified S protein, which, to the best of our knowledge, is the highest value achieved to date using insect cells. In addition, the insect cell-derived S protein exhibited glycan processing similar to mammalian cells and mid-term stability upon storage (up to 90 days at −80 and 4 °C or after 5 freeze-thaw cycles). Noteworthy, antigenicity of S protein, either as single antigen or displayed on the surface of virosomes, was confirmed by ELISA, with binding of ACE2 receptor, pan-SARS antibody CR3022 and neutralizing antibodies to the various epitope clusters on the S protein. Binding capacity was also maintained on virosomes-S stored at 4 °C for 1 month. This work demonstrates the potential of using IC-BEVS to produce the highly glycosylated and complex S protein, without compromising its integrity and antigenicity, to be included in a virosome-based COVID-19 vaccine candidate.
Plasmodium falciparum cysteine-rich protective antigen (PfCyRPA) has been identified as a promising blood-stage candidate antigen to include in a broadly cross-reactive malaria vaccine. In the last couple of decades, substantial effort has been committed to the development of scalable cost-effective, robust, and high-yield PfCyRPA production processes. Despite insect cells being a suitable expression system due to their track record for protein production (including vaccine antigens), these are yet to be explored to produce this antigen. In this study, different insect cell lines, culture conditions (baculovirus infection strategy, supplementation schemes, culture temperature modulation), and purification strategies (affinity tags) were explored aiming to develop a scalable, high-yield, and high-quality PfCyRPA for inclusion in a virosome-based malaria vaccine candidate. Supplements with antioxidants improved PfCyRPA volumetric titers by 50% when added at the time of infection. In addition, from three different affinity tags (6x-His, 4x-His, and C-tag) evaluated, the 4x-His affinity tag was the one leading to the highest PfCyRPA purification recovery yields (61%) and production yield (26 mg/L vs. 21 mg/L and 13 mg/L for 6x-His and C-tag, respectively). Noteworthy, PfCyRPA expressed using High Five cells did not show differences in protein quality or stability when compared to its human HEK293 cell counterpart. When formulated in a lipid-based virosome nanoparticle, immunized rabbits developed functional anti-PfCyRPA antibodies that impeded the multiplication of P. falciparum in vitro. This work demonstrates the potential of using IC-BEVS as a qualified platform to produce functional recombinant PfCyRPA protein with the added benefit of being a non-human expression system with short bioprocessing times and high expression levels.
Stable insect cell lines are emerging as an alternative to the insect cell-baculovirus expression vector system (IC-BEVS) for protein expression, benefiting from being a virus-free, nonlytic system. Still, the titers achieved are considerably lower. In this study, stable insect (Sf-9 and High Five) cells producing Gag virus-like particles (VLPs) were first adapted to grow under hypothermic culture conditions (22°C instead of standard 27°C), and then pseudotyped with a model membrane protein (influenza hemagglutinin [HA]) for expression of Gag-HA VLPs. Adaptation to lower temperature led to an increase in protein titers of up to 12-fold for p24 (as proxy for Gag-VLP) and sixfold for HA, with adapted Sf-9 cells outperforming High Five cells. Resulting Gag-HA VLPs producer Sf-9 cells were cultured to high cell densities, that is, 100 × 106 cell/ml, using perfusion (ATF® 2) in 1 L stirred-tank bioreactors. Specific p24 and HA production rates were similar to those of batch culture, enabling to increase volumetric titers by 7-8-fold without compromising the assembly of Gag-HA VLPs. Importantly, the antigen (HA) quantity in VLPs generated using stable adapted cells in perfusion was ≈5-fold higher than that from IC-BEVS, with the added benefit of being a baculovirus-free system. This study demonstrates the potential of combining stable expression in insect cells adapted to hypothermic culture conditions with perfusion for improving Gag-HA VLPs production.
The use of non-standard culture conditions has proven efficient to increase cell performance and recombinant protein production in different cell hosts. However, the establishment of high-producing cell populations through adaptive laboratory evolution (ALE) has been poorly explored, in particular for insect cells. In this study, insect High Five cells were successfully adapted to grow at a neutral culture pH (7.0) through ALE for an improved production of influenza hemagglutinin (HA)-displaying virus-like particles (VLPs). A stepwise approach was used for the adaptation process, in which the culture pH gradually increased from standard 6.2 to 7.0 (ΔPh = 0.2–0.3), and cells were maintained at each pH value for 2–3 weeks until a constant growth rate and a cell viability over 95% were observed. These adapted cells enabled an increase in cell-specific HA productivity up to three-fold and volumetric HA titer of up to four-fold as compared to non-adapted cells. Of note, the adaptation process is the element driving increased specific HA productivity as a pH shift alone was inefficient at improving productivities. The production of HA-VLPs in adapted cells was successfully demonstrated at the bioreactor scale. The produced HA-VLPs show the typical size and morphology of influenza VLPs, thus confirming the null impact of the adaptation process and neutral culture pH on the quality of HA-VLPs produced. This work strengthens the potential of ALE as a bioprocess engineering strategy to improve the production of influenza HA-VLPs in insect High Five cells.
Adaptive laboratory evolution (ALE) has been extensively used to modulate the phenotype of industrial model organisms (e.g. Escherichia. coli and Saccharomyces cerevisae) towards a specific trait. Nevertheless, its application to animal cells, and in particular to insect cell lines, has been very limited. In this study, we describe employing an ALE method to improve the production of HIV-Gag virus-like particles (VLPs) in stable Sf-9 and High Five cell lines. Serial batch transfer was used for evolution experiments. During the ALE process, cells were cultured under controlled hypothermic conditions (22 degrees C instead of standard 27 degrees C) for a prolonged period of time (over 3 months), which allowed the selection of a population of cells with improved phenotype. Adapted cells expressed up to 26-fold (Sf-9 cells) and 10-fold (High Five cells) more Gag-VLPs than non-adapted cells cultured at standard conditions. The production of HIV Gag-VLPs in adapted, stable insect Sf-9 cell lines was successfully demonstrated at bioreactor scale. The Gag-VLPs produced at 22 degrees C and 27 degrees C were comparable, both in size and morphology, thus confirming the null impact of adaptation process and hypothermic culture conditions on VLP's quality. This work demonstrates the suitability of ALE as a powerful method for improving yields in stable insect cell lines producing VLPs.
Conformationally complex membrane proteins (MPs) are therapeutic targets in many diseases, but drug discovery has been slowed down by the lack of efficient production tools. Co-expression of MPs with matrix proteins from enveloped viruses is a promising approach to obtain correctly folded proteins at the surface of virus-like particles (VLPs), preserving their native lipidic environment. Here, we implemented a site-specific recombinase-mediated cassette exchange (RMCE) strategy to establish a reusable HIV-1 Gag-expressing insect cell line for fast production of target MPs on the surface of Gag-VLPs. The Sf9 cell line was initially tagged with a Gag-GFP-expressing cassette incorporating two flipase recognition target sites (FRTs), one within the fusion linker of Gag-GFP. The GFP cassette was afterwards replaced by a Cherry cassette via flipase (Flp) recombination. The fusion of Gag to fluorescent proteins enabled high-throughput screening of cells with higher Gag expression and Flp-mediated cassette exchange ability, while keeping the functionality of the VLP scaffold unaltered. The best cell clone was then Flp-recombinated to produce Gag-VLPs decorated with a human β2-adrenergic receptor (β2AR). Release of a fluorescently labeled β2AR into the culture supernatant was confirmed by immunoblotting, and its co-localization with Gag-VLPs was visualized by confocal microscopy. Furthermore, the differential avidity of β2AR-dsplaying Gag-VLPs versus "naked" Gag-VLPs to an anti-β2AR antibody measured by ELISA corroborated the presence of β2AR at the surface of the Gag-VLPs. In conclusion, this novel insect cell line represents a valuable platform for fast production of MPs in their native conformation, which can accelerate small-molecule and antibody drug discovery programs.
The objective of this study was evaluated the villus integrity of commercial turkeys submitted to coccidiosis prevention methods and challenged with Eimeria field oocysts, using scanning electron microscopy. Sixty BUT 9 female commercial turkeys were distributed in a completely randomized block design split with two treatments: T1- control diet without vaccinations against coccidiosis and anticoccidial drug, and T2- vaccinated against coccidiosis (commercial vaccine). On d 21 of life, all birds of all treatments were challenged with a mixed-species containing E. meleagrimitis and E. galopavonis, via crop intubation with 1 mL of ~20,000 sporulated oocysts/bird. The size of the inoculum was determined in previous experiments. At 27 and 70 days of age, five birds per treatment were randomly removed to evaluate the intestinal integrity. Duodenum, jejunum and ileum segments were collected and processed according to routine scanning electron microscope. The enteric mucosa integrity of the commercial turkeys subjected to coccidiosis vaccination was reduced when compared to the birds of the control treatment. There was no difference in the performance results, therefore these results cannot be attributed to the vaccination as well as to the ineffectiveness against the challenge that was administered.
ABSTRACT Pododermatitis, also known as "bumblefoot", is an inflammatory lesion of the footpad. The objective of this study was to evaluate the influence of genetic strain and sex on the incidence of footpad lesions in broilers. The experiment was carried out at São Paulo State University, using 480 broilers distributed in a completely randomized experimental design in a 2X2 factorial arrangement (2 strains X2 sexes), with four replicates of 30 broilers each, totaling 16 experimental units. Feed intake, weight gain, feed conversion ratio, and livability were evaluated at 21, 35 and 42 days of age; production efficiency factor was determined at the end of the rearing period. On day 42, the footpads of 100 broilers were grossly examined and assigned a lesion score in a 1-3 scale (Almeida Paz & Martins, 2014). Three samples per score within treatment were collected for microscopic evaluation. Analysis of variance was applied and performance parameter means were compared by Tukey's test. Footpad lesion incidence was analyzed by the c2 test using SAS (version8.2). Ross(r) broilers presented higher feed intake during all evaluated periods, and higher weight gain only in the period 1 to 21 days compared with Cobb(r) broilers. On the other hand, Cobb(r) presented better feed conversion ratio in the periods of 1 to 35 and 1 to 42 days. The incidence of foot pad lesions was statistically different (p< 0.05) between strains and sexes, but there were no interactions between these factors. The lesion scores assigned were compatible with the histopathological results, showing that the higher the score, the more severe were the dermal and epidermal lesions.
Seringas e agulhas hipodérmicas são produtos para saúde. Além da tramitação do registro junto à Anvisa, é imprescindível realizar a vigilância pós-comercialização para disponibilizar produtos seguros e eficazes no mercado. O elevado número de notificações à Anvisa, levou à publicação de regulamentos técnicos específicos e à obrigatoriedade da certificação compulsória. Este estudo analisou os resultados obtidos na avaliação da embalagem primária, do rótulo e do aspecto de seringas e agulhas disponíveis no almoxarifado de um Hospital Sentinela antes e depois da exigência de certificação compulsória. A primeira coleta ocorreu em 2012, após a publicação dos regulamentos técnicos, e a segunda coleta foi realizada em 2014, após a obrigatoriedade de certificação compulsória. Na avaliação do rótulo, todas as amostras foram consideradas satisfatórias. Na análise de aspecto, foram reprovados 62,5% dos produtos analisados em 2012 e 50% em 2014, gerando um total de 56% de reprovação nos dois anos. As “não conformidades” mais encontradas foram: o excesso de lubrificante e a vulnerabilidade da embalagem. O estudo demonstrou que a obrigatoriedade da certificação, por si só, não garante a qualidade sanitária, mas reafirma a necessidade da atividade de pós-comercialização, bem como a estratégia positiva das parcerias de serviços de saúde com laboratórios oficiais e na aquisição racional de produtos e redução do risco.