The pharyngeal taste organ of a blood-feeding insect functions in food recognition.

BACKGROUND: Obligate blood-feeding insects obtain the nutrients and water necessary to ensure survival from the vertebrate blood. The internal taste sensilla, situated in the pharynx, evaluate the suitability of the ingested food. Here, through multiple approaches, we characterized the pharyngeal organ (PO) of the hematophagous kissing bug Rhodnius prolixus to determine its role in food assessment. The PO, located antero-dorsally in the pharynx, comprises eight taste sensilla that become bathed with the incoming blood. RESULTS: We showed that these taste sensilla house gustatory receptor neurons projecting their axons through the labral nerves to reach the subesophageal zone in the brain. We found that these neurons are electrically activated by relevant appetitive and aversive gustatory stimuli such as NaCl, ATP, and caffeine. Using RNA-Seq, we examined the expression of sensory-related gene families in the PO. We identified gustatory receptors, ionotropic receptors, transient receptor potential channels, pickpocket channels, opsins, takeouts, neuropeptide precursors, neuropeptide receptors, and biogenic amine receptors. RNA interference assays demonstrated that the salt-related pickpocket channel Rproppk014276 is required during feeding of an appetitive solution of NaCl and ATP. CONCLUSIONS: We provide evidence of the role of the pharyngeal organ in food evaluation. This work shows a comprehensive characterization of a pharyngeal taste organ in a hematophagous insect.

Emulgel based on fish skin collagen-microalgae-silver increased neovascularization and re-epithelialization of full thickness burn in rats.

Deep skin burn represents a global morbidity and mortality problem, and the limitation of topical treatment agents has motivated research to development new formulations capable of preventing infections and accelerating healing. The aim of this work was to develop and characterize an emulgel based on collagen (COL) and gelatin (GEL) extracted from fish skin associated with Chlorella vulgaris extract (CE) and silver nitrate (AgNO3). COL and GEL were characterized by physicochemical and thermal analyses; and CE by electrophoresis and its antioxidant capacity. Three emulgels formulations were developed: COL (0.5%) + GEL (2.5%) (E1), COL+GEL+CE (1%) (E2), and COL+GEL+CE + AgNO3 (0.1%) (E3). All formulations were characterized by physicochemical, rheology assays, and preclinical analyses: cytotoxicity (in vitro) and healing potential using a burn model in rats. COL and GEL showed typical physicochemical characteristics, and CE presented 1.3 mg/mL of proteins and antioxidant activity of 76%. Emulgels presented a coherent physicochemical profile and pseudoplastic behavior. Preclinical analysis showed concentration-dependent cytotoxicity against fibroblast and keratinocytes. In addition, all emulgels induced similar percentages of wound contraction and complete wound closure in 28 days. The histopathological analysis showed higher scores for polymorphonuclear cells to E1 and greater neovascularization and re-epithelialization to E3. Then, E3 formulation has potential to improve burn healing, although its use in a clinical setting requires further studies.

Female Aedes aegypti mosquitoes use communal cues to manage population density at breeding sites.

Where a female mosquito lays her eggs creates the conditions for reproductive success. Here we identify a communal behavior among ovipositing female mosquitoes. When choosing equal breeding sites, gravid Aedes aegypti aggregate more often than expected. This aggregation occurs when water contact is restricted and does not require the presence of eggs. Instead, the aggregation is regulated by the number of females present at the breeding site. Using assays with both occupied and empty oviposition sites, we show that the Orco olfactory co-receptor and a carbon dioxide receptor, Gr3, detect the presence of mosquitoes. orco mutants aggregate more often in empty sites, suggesting attractive olfactory cues influence females to associate with one another. Gr3 mutant females do not prefer either site, suggesting that the CO2 receptor is necessary to evaluate mosquito population density at breeding sites. Further, raising CO2 levels is sufficient to cause wild-type mosquitoes to avoid empty oviposition sites. Our results demonstrate that female mosquitoes can regulate their own population density at breeding sites using attractive and repellent communal cues.

Galectin-9 is a target for the treatment of cancer: A patent review.

Galectins, which correspond to a group of proteins capable of recognizing and reversibly binding to ß-galactoside carbohydrates, have been the subject of innovation and development of technological products. Galectins play biological roles, such as cell proliferation and apoptosis, and some studies showed differences in the concentrations of galectins dispersed in serum of patients with cancer. For this reason, different studies have evaluated the biotechnological potential of these proteins as biomarkers for the prognosis and/or diagnosis of physiological disorders. Thus, this review discusses recent technological advancements in targeting galectins for the treatment of cancer and using galectins for cancer prognosis and diagnosis. Data mining was performed using the search descriptors "Galectin 9* and cancer*" and the ESPACENET and Cortellis Drug Discovery Intelligence (CDDI) databases. PRISMA guidelines were followed as a basis for literature review which aimed to conduct a systematic study of galectin-9 patents related to cancer prognosis, diagnosis and treatment. Results showed the importance of galectin-9 protein patents in furthering biomedical advancements in the global fight against cancer.

Vitellogenin genes are transcribed in Culex quinquefasciatus ovary.

BACKGROUND: Culex quinquefasciatus, a cosmopolitan, domestic, and highly anthropophilic mosquito, is a vector of pathogenic arboviruses such as West Nile virus and Rift Valley virus, as well as lymphatic filariasis. The current knowledge on its reproductive physiology regarding vitellogenin expression in different tissues is still limited. OBJECTIVES: In this study, we analysed the transcriptional profiles of vitellogenin genes in the fat body and ovaries of C. quinquefasciatus females during the first gonotrophic cycle. METHODS: C. quinquefasciatus ovaries and/or fat bodies were dissected in different times during the first gonotrophic cycle and total RNA was extracted and used for reverse transcription polymerase chain reaction, quantitative real time-PCR, and in situ hybridisation. FINDINGS: We confirmed the classical descriptions of the vitellogenic process in mosquitoes by verifying that vitellogenin genes are transcribed in the fat bodies of C. quinquefasciatus females. Using RNA in situ hybridisation approach, we showed that vitellogenin genes are also transcribed in developing ovaries, specifically by the follicle cells. MAIN CONCLUSIONS: This is the first time that vitellogenin transcripts are observed in mosquito ovaries. Studies to determine if Vg transcripts are translated into proteins and their contribution to the reproductive success of the mosquito need to be further investigated.

Fertility decline in female mosquitoes is regulated by the orco olfactory co-receptor.

Female Aedes aegypti mosquitoes undergo multiple rounds of reproduction, known as gonotrophic cycles. These cycles span the period from blood meal intake to oviposition. Understanding how reproductive success is maintained across gonotrophic cycles allows for the identification of molecular targets to reduce mosquito population growth. Odorant receptor co-receptor (orco) encodes a conserved insect-specific transmembrane ion channel that complexes with tuning odorant receptors (ORs) to form a functional olfactory receptor. orco expression has been identified in the male and female mosquito germline, but its role is unclear. We report an orco-dependent, maternal effect reduction in fertility after the first gonotrophic cycle. This phenotype was removed by CRISPR-Cas9 reversion of the orco mutant locus. Eggs deposited by orco mutant females are fertilized but the embryos reveal developmental defects, reduced hatching, and changes in ion channel signaling gene transcription. We present an unexpected role for an olfactory receptor pathway in mosquito reproduction.

Cost-effectiveness of selective internal radiation therapy with Y-90 resin microspheres for intermediate- and advanced-stage hepatocellular carcinoma in Brazil.

AIMS: Hepatocellular carcinoma (HCC) is a severe condition with poor prognosis that places a significant burden on patients, caregivers, and healthcare systems. Selective internal radiation therapy (SIRT) is a treatment available to patients with HCC which addresses some of the limitations of alternative treatment options. A cost-effectiveness analysis was undertaken into the use of SIRT using Y-90 resin microspheres for the treatment of unresectable intermediate- and late-stage HCC in Brazil. MATERIALS AND METHODS: A partitioned-survival model was developed, including a tunnel state for patients downstaged to receive treatments with curative intent. Sorafenib was the selected comparator, a common systemic treatment in Brazil and for which comparative evidence exists. Clinical data were extracted from published sources of pivotal trials, and effectiveness was measured in quality-adjusted life-years (QALYs) and life-years (LYs). The analysis was conducted from the Brazilian private payer perspective and a lifetime horizon was implemented. Comprehensive sensitivity analyses were conducted. RESULTS: LYs and QALYs were higher for SIRT with Y-90 resin microspheres versus sorafenib (0.27 and 0.20 incremental LYs and QALYs, respectively) and costs were slightly higher for SIRT (R$15,864). The base case incremental cost-effectiveness ratio (ICER) was R$77,602 per QALY. The ICER was mostly influenced by parameters defining the sorafenib overall survival curve and SIRT had a 73% probability of being cost-effective at a willingness-to-pay threshold of R$135,761 per QALY (3-times the per-capita gross domestic product in Brazil). Overall, sensitivity analyses confirmed the robustness of the results indicating that SIRT with Y-90 resin microspheres is cost-effective compared with sorafenib. LIMITATIONS: A rapidly evolving treatment landscape in Brazil and worldwide, and the lack of local data for some variables were the main limitations. CONCLUSIONS: SIRT with Y-90 resin microspheres is a cost-effective option compared with sorafenib in Brazil.

Artificial Membrane Feeding Mosquitoes in the Laboratory with Glytube.

Artificial membrane feeders are devices that replace vertebrate hosts when blood feeding mosquitoes. Created using readily available materials found in mosquito laboratories, Glytube is one of the simplest artificial membrane feeders that scientists can use to provide a blood meal to female mosquitoes in the laboratory. Glytube was optimized for blood feeding the main epidemiologically important species, such as Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and Anopheles aquasalis Although the Glytube can be used without modifications to blood feed mosquito females, some researchers have modified the device to improve its assembly and to adapt it to different feeding assays that do not involve a basic blood meal, broadening its utility. Here, I describe how to transform a 50-mL conical centrifuge tube into a convenient, versatile, and cost-effective artificial membrane blood feeder.

Membrane Feeding Devices to Blood Feed Mosquitoes in the Laboratory.

Husbandry protocols for medically important mosquito species in the laboratory have the blood feeding procedure as an inherent step in the maintenance routine for egg production. Artificial feeders have become the main solution for delivering blood meals to these hematophagous insects, circumventing the need for vertebrate hosts. Mimicking the skin, these devices both heat the blood and hold a membrane through which the blood can be ingested by mosquitoes. Several commercial and noncommercial artificial mosquito feeders are available, but obstacles like high cost and complex assembly can restrict their routine use. To address this issue, a number of feeders have been designed that can be built with common materials found in the laboratory. They are cheaper and more accessible, but the absence of built-in temperature control and heating units can limit their efficacy. One of the most accessible mosquito feeders is the Glytube. It consists of a 50-mL conical centrifuge tube with heated glycerol that delivers blood through a membrane. The Glytube has been used successfully to model mosquito blood feeding. Recently, 3D printing has emerged as an alternative method to create customized artificial feeders. This technology is expected to facilitate access to and reduce the cost of these devices with open-source 3D model files that can be shared among laboratories maintaining mosquitoes worldwide.

Extraction and characterization of hyaluronic acid from the eyeball of Nile Tilapia (Oreochromis niloticus).

Hyaluronic acid (HA) is a biopolymer of enormous value aggregation for in general industry. The vitreous humor of the eyeball from Nile tilapia contains appreciable amounts of hyaluronic acid. In this sense, the aim of this work was to extract and characterize hyaluronic acid from the eyeball of the Nile tilapia for biomedical applications, adding value to fish industry residues. The characterization by infra-red (FTIR), 13C nuclear magnetic resonance (NMR) and high performance liquid chromatography (HPLC) confirmed that hyaluronic acid was obtained. The gel permeation chromatography (GPC) showed that the obtained material presents a low molecular mass (37 KDa). Thermogravimetry (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) analysis showed that the materials present a thermal stability superior to the commercial hyaluronic acid from Streptococcus equi, with a partially crystalline character. The cytotoxicity assay (MTT method) with fibroblast cells (L929) demonstrated that the extracted biopolymer besides not being cytotoxic, was able to stimulate cell proliferation. Therefore, the hyaluronic acid extracted from this source of residue constitutes a product with biotechnological potential, which has adequate quality for wide biomedical applications.

Transcriptome profiling and Calreticulin expression in Zika virus -infected Aedes aegypti.

Zika virus (ZIKV) may cause febrile illness and neurological damage, such as microcephaly in fetuses. ZIKV is transmitted to humans by Aedes aegypti, a nearly cosmopolitan mosquito. Understanding the virus-vector molecular interactions has been promising to enhance the knowledge towards disease mitigation. Since ZIKV infection alters gene physiology of mosquitoes, we examined the expression profile of ZIKV-infected Ae. aegypti by several approaches to identify genes altered by viral infection. Transcriptomics were performed by comparing between ZIKV-infected and uninfected Ae. aegypti females, which revealed some differentially expressed genes. Most of these genes appear to be involved with immune response as evidenced by an interactome analysis, and a prominent finding was a calreticulin-like (CRT) gene, which was upregulated during the infection. Expression of CRT was also experimentally quantified by qPCR, however, it revealed no significant differences between infected and uninfected females. Instead, expression levels were highly variable among individuals and negatively correlated to viral load. We also tested the possibility of this gene to be silenced, but the double-stranded RNA did not reduce CRT expression, and actually increased the inter-individuals' expressional variability. Present results differed from our original hypothesis of upregulation by infection. They also diverged between them (comparing qPCR to Transcriptomics) and from the literature which reported augmented CRT levels in Aedes species during viral infection. Present case probably underlies a more complex virus-host interaction system than we expected. Regulation of this gene seems not to be a linear correlation between expression and viremy. As infection takes place, a complex homeostatic mechanism may act to prevent expression and other cellular tasks from drifting. It is also possible that CRT expression is simply randomly disturbed by viral infection. Taken together, results show that CRT expression profile during ZIKV infection is complex and requires different investigative approaches to be understood. Studies focused on the biochemical function of CRT protein and on its role in the native mosquito metabolic network could unravel how it is actually influenced by ZIKV. Current work contributes more by getting incidental findings and by posing new hypotheses than by answering the original questions.

Vitellogenin genes are transcribed in Culex quinquefasciatus ovary

BACKGROUND Culex quinquefasciatus, a cosmopolitan, domestic, and highly anthropophilic mosquito, is a vector of pathogenic arboviruses such as West Nile virus and Rift Valley virus, as well as lymphatic filariasis. The current knowledge on its reproductive physiology regarding vitellogenin expression in different tissues is still limited. OBJECTIVES In this study, we analysed the transcriptional profiles of vitellogenin genes in the fat body and ovaries of C. quinquefasciatus females during the first gonotrophic cycle. METHODS C. quinquefasciatus ovaries and/or fat bodies were dissected in different times during the first gonotrophic cycle and total RNA was extracted and used for reverse transcription polymerase chain reaction, quantitative real time-PCR, and in situ hybridisation. FINDINGS We confirmed the classical descriptions of the vitellogenic process in mosquitoes by verifying that vitellogenin genes are transcribed in the fat bodies of C. quinquefasciatus females. Using RNA in situ hybridisation approach, we showed that vitellogenin genes are also transcribed in developing ovaries, specifically by the follicle cells. MAIN CONCLUSIONS This is the first time that vitellogenin transcripts are observed in mosquito ovaries. Studies to determine if Vg transcripts are translated into proteins and their contribution to the reproductive success of the mosquito need to be further investigated.

Transcriptome profiling and Calreticulin expression in Zika virus-infected Aedes aegypti

Zika virus (ZIKV) may cause febrile illness and neurological damage, such as microcephaly in fetuses. ZIKV is transmitted to humans by Aedes aegypti, a nearly cosmopolitan mosquito. Understanding the virus-vector molecular interactions has been promising to enhance the knowledge towards disease mitigation. Since ZIKV infection alters gene physiology of mosquitoes, we examined the expression profile of ZIKV-infected Ae. aegypti by several approaches to identify genes altered by viral infection. Transcriptomics were performed by comparing between ZIKV-infected and uninfected Ae. aegypti females, which revealed some differentially expressed genes. Most of these genes appear to be involved with immune response as evidenced by an interactome analysis, and a prominent finding was a calreticulin-like (CRT) gene, which was upregulated during the infection. Expression of CRT was also experimentally quantified by qPCR, however, it revealed no significant differences between infected and uninfected females. Instead, expression levels were highly variable among individuals and negatively correlated to viral load. We also tested the possibility of this gene to be silenced, but the double-stranded RNA did not reduce CRT expression, and actually increased the inter-individuals' expressional variability. Present results differed from our original hypothesis of upregulation by infection. They also diverged between them (comparing qPCR to Transcriptomics) and from the literature which reported augmented CRT levels in Aedes species during viral infection. Present case probably underlies a more complex virus-host interaction system than we expected. Regulation of this gene seems not to be a linear correlation between expression and viremy. As infection takes place, a complex homeostatic mechanism may act to prevent expression and other cellular tasks from drifting. It is also possible that CRT expression is simply randomly disturbed by viral infection. Taken together, results show that CRT expression profile during ZIKV infection is complex and requires different investigative approaches to be understood. Studies focused on the biochemical function of CRT protein and on its role in the native mosquito metabolic network could unravel how it is actually influenced by ZIKV. Current work contributes more by getting incidental findings and by posing new hypotheses than by answering the original questions.

Telehealth Strategies to Support Referral Management to Secondary Care in Brazil: A Cost-Effectiveness Analysis.

OBJECTIVES: This study aimed to assess the cost-effectiveness of a remotely operated referral management system (RORMS) compared with a conventional referral management system (CRMS) in Brazil. METHODS: This is a model-based cost-effectiveness analysis under the perspective of the Unified Healthcare System (Sistema Único de Saúde [SUS]) in Brazil. A Markov microsimulation model was developed to compare costs and referral outcomes of the RORMS and the CRMS. Model consisted of 4 states representative of sequential stepwise assessments of referral suitability, 3 states representative of referral outcomes, and 1 exit model state. Target population represented cases being referred from primary healthcare units to specialized care in SUS. Model inputs related to costs and effectiveness in the RORMS arm were obtained from the data set of a RORMS between July and December 2019. Model inputs for the CRMS model arm were obtained from administrative data sets of 2 Brazilian localities for the year 2019. Relative effect size of RORMS in comparison with CRMS in SUS was obtained from published studies. Effectiveness outcome was unnecessary referrals averted. The incremental cost-effectiveness ratio was calculated for the base case. Probabilistic sensitivity analysis was conducted. RESULTS: In the base-case analyses, RORMS dominated CRMS, with expected cost-savings from $50.42 to $80.62 per unnecessary referral averted. RORMS was the dominant strategy in 83.7% of 100 000 simulations in the probabilistic sensitivity analysis. In 16.2% of simulations, incremental cost-effectiveness ratio was between $0 and $222 per unnecessary referral averted. CONCLUSIONS: Model-based simulations indicate that the RORMS is likely to be cost saving in comparison with the CRMS.

A Educação Física no Núcleo Ampliado à Saúde da Família ­ Atenção Básica: o caso da cidade de Vitória/ES / Physical Education in the Extended Center for Family Health - Primary Care: the case of the city of Vitória/ES / La Educación Física en el Núcleo Ampliado de Salud de la Familia - Atención Primaria: el caso de la ciudad de Vitória/ES

Este estudo objetiva analisar a caracterização das práticas de saúde de campo comum dos profissionais de Educação Física no Núcleo Ampliado à Saúde da Família ­ Atenção Básica/NASF-AB da cidade de Vitória/ES. A construção coletiva dos dados ocorreu por meio de observação participante, de diário de campo e de entrevista coletiva. Tal produção de dados permitiu análises coletivas com o grupo participante e mapeamento das práticas de saúde desenvolvidas por oito profissionais de Educação Física. A sistematização e o tratamento analítico dos dados possibilitaram a elaboração de duas temáticas: a participação do profissional de Educação Física nas reuniões de Equipe de Saúde da Família; e NASF-AB e práticas e intervenções de campo comum pelo/a PEF do NASFAB. Concluímos que os/as PEF do NASF-AB de Vitória/ES vêm desenhando suas práticas e saberes nos tensionamentos e encontros com os problemas nos territórios e com as equipes multiprofissionais de saúde.

This study aims to analyze the characterization of common field health practices of Physical Education professionals in the Extended Family Health Center - Primary Care/NASF-AB of the city of Vitória/ES. The collective construction of the data occurred through participant observation, field diary and collective interview. This data production allowed collective analyses with the participating group and mapping of health practices developed by eight Physical Education professionals. The systematization and analytical treatment of the data made it possible to develop two themes: the participation of the Physical Education professional in the meetings of the Family Health Team and NASF-AB; and common field practices and interventions by the NASF-AB PEF. We conclude that the PEF of the NASF-AB of Vitória/ES have been designing their practices and knowledge in tensionings and encounters with problems in the territories and with multidisciplinary health teams.

Este estudio tiene como objetivo analizar la caracterización de las prácticas de salud en el campo común de los profesionales de educación física en el Centro Ampliado de Salud de la Familia ­ Atención Básica-NASF-AB en la ciudad de Vitória/ES. La construcción colectiva de los datos se realizó a través de la observación participante, diario de campo y entrevista colectiva. Tal producción de datos permitió análisis colectivos con el grupo participante y mapeo de las prácticas de salud desajolladas por ocho profesionales de Educación Física. La sistematización y tratamiento analítico de los datos hizo posible la elaboración de dos temas: la participación del profesional de Educación Física en los encuentros del Equipo de Salud de la Familia y NASF-AB y; prácticas e intervenciones de campo comunes por parte del PEF de lo NASF-AB. Concluimos que los PEF de lo NASF-AB de Vitória/ES vienen diseñando sus prácticas y saberes en las tensiones y encuentros con los problemas en los territorios y con los equipos multiprofesionales de salud.

The Usefulness of a Facial Digital Biobank for Ameloblastoma Resection and Fracture Fixation - A Case Report.

Rationale: Ameloblastoma often requires complex facial treatments such as resection and reconstruction, which can be aided using three-dimensional resources towards improved surgical planning, reduction of surgical time, and customization. Patient Concerns: A 51-year-old patient, concerned about submandibular volumetric increase discovered performing imaging exams to install dental implants. Diagnosis and Treatment: Diagnosed with ameloblastoma, he underwent uneventful partial mandibular resection and placement of prebent mandibular reconstruction plate. Four months later, following a motorcycle accident, a deflection of the plate and mandibular fracture was observed. Using the initial prototyping, a new reconstruction plate was customized and surgically placed to reduce the mandibular fracture, with adequate titanium plate adaptation to the remaining bone and maintenance of aesthetic mandibular contour. Outcomes and Take-away Lessons: The current digital dentistry resources, such as computed tomography and intraoral scan, can be recovered and used as a backup of recorded anatomy anytime in future, providing a long-lasting facial digital biobank.

Cost-effectiveness of a canine visceral leishmaniasis control program in Brazil based on insecticide-impregnated collars.

INTRODUCTION: The use of insecticide-impregnated dog collars is a potentially useful tool for the control of visceral leishmaniasis. The objective of the present study was to perform a cost-effectiveness analysis of a program based on insecticide-impregnated collars compared to traditional visceral leishmaniasis control strategies used in Brazil. METHODS: A cost-effectiveness analysis was performed from the perspective of the Unified Health System, using data from the Visceral Leishmaniasis Control Program implemented in the municipality of Montes Claros, Minas Gerais. The direct costs of the three control strategies, which were 1) canine infection screening + sacrifice, 2) residual chemical control of the vector, and 3) insecticide-impregnated dog collars (Scalibor®), were evaluated over the two-year study period. RESULTS: The total cost of the program in the area subjected to the traditional control strategies (strategies 1 and 2; control area) was R$ 1,551,699.80, and in the area subjected to all three control strategies (intervention area), it was R$ 1,898,190.16. The collar program was considered highly cost-effective at preventing canine visceral leishmaniasis (incremental cost-effectiveness ratio of approximately R$ 578 per avoided dog sacrifice). CONCLUSIONS: These results provide support for the decision by the Brazilian Ministry of Health in 2019 to provide insecticide-impregnated collars for the control of canine visceral leishmaniasis in a pilot project.

A Metagenomic Approach Identified a Novel Phasi Charoen-Like Virus Coinfecting a Chikungunya Virus-Infected Aedes aegypti Mosquito in Brazil.

Insect-specific viruses do not replicate in vertebrates. Here, we report the genome sequence of a novel strain of a Phasi Charoen-like virus (PCLV) that was isolated from a wild Aedes aegypti mosquito collected in Aracajú, Sergipe State, Brazil. The coding-complete genome of the PCLV is described in this report.

Effects of silylated starch structure on hydrophobization and mechanical properties of thermoplastic starch foams made from potato starch.

Non-biodegradable single use packaging are a serious environmental problem as it generates large amounts of waste and is generally not recycled. These packages, especially those made of expanded polystyrene, can be replaced by thermoplastic starch foams. These foams have the advantage of being from renewable sources and biodegradable. However, this material is hydrophilic and becomes unusable when it is exposed to water. Hydrophobizing starch comes as an alternative to make the foams more resistant to contact with water. The purpose of the modification is to exchange starch hydroxyl groups for less polar groups such as silane groups. In this work, two silanes were used for starch silylation: 3-chloropropyl trimethoxysilane and Methyltrimethoxysilane. The foams were made using four materials: modified starch, gelatinized starch, polyvinyl alcohol and water. Results from water absorption tests and mechanical tests show that foams absorb less water and become more resistant with the addition of silylated starch.