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1.
BMC Infect Dis ; 24(1): 438, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658871

RESUMO

BACKGROUND: Herpes Zoster is an age dependent disease and as such it represents a problem in the Italian social context, where the demographic curve is characterized by an overrepresentation of the elderly population. Vaccines against Herpes Zoster are available, safe and effective, however coverage remains sub-optimal. This study was therefore conducted to examine the variations in Herpes Zoster vaccine uptake and confidence across different regions in Italy. METHODS: This study utilized a cross-sectional computer-assisted web interview (CAWI) methodology. The survey was conducted by Dynata, an online panel provider, and involved 10,000 respondents recruited in Italy between April 11 and May 29, 2022. The sample was stratified based on geographic region, gender, and age group. Data management adhered to European Union data protection regulations, and the survey covered demographics, living conditions, and vaccination against herpes zoster (HZ), following the BeSD framework. RESULTS: The findings indicate regional disparities in herpes zoster vaccine uptake across Italy. Notably, the Islands region exhibits a particularly low vaccination rate (2.9%), highlighting the need for targeted interventions. The multivariate regression analysis showed that sociodemographic factors, limited access to healthcare services, and inadequate awareness of vaccine eligibility contribute to the lower uptake observed in this region. CONCLUSION: In conclusion, this research emphasizes regional disparities in herpes zoster (HZ) vaccination uptake in Italy. Demographic, socioeconomic, and geographic factors impact individuals' willingness to receive the vaccine. The study highlights the importance of awareness of vaccine eligibility and accessible vaccination facilities in increasing uptake rates.


Assuntos
Vacina contra Herpes Zoster , Herpes Zoster , Cobertura Vacinal , Humanos , Itália/epidemiologia , Estudos Transversais , Masculino , Feminino , Herpes Zoster/prevenção & controle , Herpes Zoster/epidemiologia , Pessoa de Meia-Idade , Vacina contra Herpes Zoster/administração & dosagem , Idoso , Adulto , Cobertura Vacinal/estatística & dados numéricos , Adulto Jovem , Vacinação/estatística & dados numéricos , Adolescente , Inquéritos e Questionários , Idoso de 80 Anos ou mais
2.
BMC Public Health ; 24(1): 736, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38454392

RESUMO

BACKGROUND: Streptococcus pneumoniae infections, including Invasive Pneumococcal Diseases (IPDs), pose a substantial public health challenge, causing significant morbidity and mortality, especially among children and older adults. Vaccination campaigns have played a vital role in reducing pneumococcal-related deaths. However, obstacles related to accessibility and awareness might impede optimal vaccine adoption. This study aims to provide comprehensive data on pneumococcal vaccine coverage and attitudes within at-risk groups in Italy, with the goal of informing public health strategies and addressing vaccination barriers. METHODS: Between April 11 and May 29, 2022, a questionnaire investigating vaccine uptake and attitudes toward several vaccinations was administered to 10,000 Italian adults, chosen through population-based sampling. Respondents who were targets of the campaign according to the 2017-2019 National Vaccination Plan, accessed questions regarding pneumococcal vaccination. Data on uptake, awareness of having the right to free vaccination, opinion on vaccine safety, concern with pneumococcal disease, and ease of access to vaccination services were summarized and presented based on statistical regions. Multinomial logistic regression analysis was used to explore factors influencing vaccine uptake. RESULTS: Out of 2357 eligible adult respondents (42.6% women; mean age: 58.1 ± 15.7), 39.5% received pneumococcal vaccination. Uptake differed among at-risk groups: respondents aged ≥65 (33.7%), with lung disease (48.4%), cardiovascular disease (46.6%), and diabetes (53.7%). Predictors of not being vaccinated and unwilling to included female gender, residing in rural areas, lower education, low concern about pneumococcal disease, vaccine safety concerns, and associations with vaccine-opposed acquaintances. Health access issues predicted willingness to be vaccinated despite non-vaccination. Pneumopathy, heart disease, diabetes, and living in Northeastern or Central Italy were linked to higher uptake. Among the 1064 parents of eligible children, uptake was 79.1%. Parental unawareness of children's free vaccination eligibility was a predictor of non-vaccination. Vaccine safety concerns correlated with reluctance to vaccinate children, while perceived healthcare access challenges were associated with wanting but not having received vaccination. CONCLUSIONS: Pneumococcal vaccination uptake within prioritized groups and children in Italy remains inadequate. Scarce awareness of vaccine availability and obstacles in accessing vaccinations emerge as principal barriers influencing this scenario.


Assuntos
Diabetes Mellitus , Infecções Pneumocócicas , Criança , Humanos , Feminino , Idoso , Adulto , Pessoa de Meia-Idade , Masculino , Vacinas Pneumocócicas , Vacinação , Inquéritos e Questionários , Infecções Pneumocócicas/prevenção & controle
3.
BMC Public Health ; 24(1): 770, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38475736

RESUMO

INTRODUCTION: The World Health Organization defines rotavirus as among the most severe causes of viral gastroenteritis affecting children under 5 year old. Italy and other European countries do not release disaggregated data on rotavirus vaccination coverage. This study aimed to assess the uptake and drivers of rotavirus vaccination in Italy. METHODS: We administered a survey to 10,000 Italian citizens recruited via an online panel and proportionate to key demographic strata. We examined rotavirus vaccine uptake among parents whose youngest child was aged 6 weeks to 4 years, their sociodemographic characteristics, their beliefs about vaccine administration, and who recommended the rotavirus vaccination. RESULTS: A total of 711 respondents met the inclusion criteria for the rotavirus vaccine questionnaire. The uptake was estimated at 60.3% nationwide (66.4% among mothers and 50.2% among fathers). Being a mother and living in cities/suburbs was significantly associated with a higher likelihood of vaccine uptake, while fathers were more likely to be uncertain of their children's vaccine status. Living in Central Italy and having friends/relatives opposed to vaccination were found to be significantly associated with a lower likelihood of vaccine uptake, while parents' education level and children's demographics were not found to correlate with any outcomes. In 90.3% of cases, the rotavirus vaccination was recalled as being recommended by a paediatrician. CONCLUSIONS: Consistent collection of behavioural preferences and socioeconomic characteristics of recipients of rotavirus vaccine campaigns, their epidemiological information, cost-benefit, and national policy data are crucial for designing effective vaccination strategies in Italy and other European countries with similar social profiles to reach the target uptake.


Assuntos
Infecções por Rotavirus , Vacinas contra Rotavirus , Rotavirus , Criança , Feminino , Humanos , Lactente , Pré-Escolar , Estudos Transversais , Infecções por Rotavirus/prevenção & controle , Vacinação , Itália
4.
Vaccines (Basel) ; 12(2)2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38400170

RESUMO

BACKGROUND: Human Papillomavirus (HPV) vaccination rates are still below the target due to vaccine refusal or delay, lack of knowledge, and logistical challenges. Understanding these barriers is crucial for developing strategies to improve HPV vaccination rates. METHODS: This cross-sectional study used a questionnaire to investigate social and behavioral factors influencing decision making about the HPV vaccine. The survey was conducted from 11 April to 29 May 2022 and involved 10,000 Italian citizens aged ≥ 18 years. The sample was stratified based on region of residence, gender, and age group. RESULTS: 3160 participants were surveyed about themselves, while 1266 respondents were surveyed about their children's vaccine uptake. Among females aged ≥ 26 years, the national average HPV vaccine uptake was 21.7%, with variations across different regions. In the 18-25 age group, females had a vaccine uptake (80.8%) twice as much as males (38.1%), while vaccine uptake among male and female children aged 9-11 was similar. CONCLUSIONS: The OBVIOUS study in Italy reveals factors influencing low HPV vaccine uptake, suggesting targeted approaches, tailored information campaigns, heightened awareness of eligibility, promoting early vaccination, addressing low-risk perception among males, addressing safety concerns, and enhancing perceived accessibility to improve vaccine uptake and mitigate health risks.

5.
Hum Vaccin Immunother ; 19(2): 2252250, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37846766

RESUMO

Influenza annually claims an estimated 8,000 lives in Italy. Despite no-cost vaccinations for high-risk groups, hesitancy persists. This study aims to pinpoint social and behavioral vaccination determinants, forming strategies to bolster vaccine uptake. From April 11 to May 29, 2022, we surveyed a demographic-stratified sample of 10,000 Italian adults, employing the WHO's Behavioral and Social Drivers of Vaccination (BesD) framework. Of those, 4,613 (46.1%) were eligible for the influenza vaccine and included in the analysis. Roughly a third remained unvaccinated and unwilling. Central Italy showed the highest resistance, with significant percentages of seniors and professionals like teachers, law enforcement, and healthcare workers expressing noncompliance. A lack of awareness of being in a target group correlated significantly with vaccine refusal or delayed acceptance. Other refusal factors included female gender, being aged 45-54, rural residency, absence of higher education, perceived vaccine unsafety, and having vaccine-opposed acquaintances. Thus, addressing these perceptions and enhancing awareness can potentially increase vaccination rates and lessen disease impact.


Assuntos
Vacinas contra Influenza , Influenza Humana , Adulto , Humanos , Feminino , Influenza Humana/prevenção & controle , Aceitação pelo Paciente de Cuidados de Saúde , Conhecimentos, Atitudes e Prática em Saúde , Vacinação , Itália
6.
Vaccines (Basel) ; 11(4)2023 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-37112751

RESUMO

BACKGROUND: Vaccine hesitancy was defined by the World Health Organization (WHO) in 2019 as a major threat to global health. In Italy, reluctance to receive vaccines is a widespread phenomenon that was amplified during the COVID-19 pandemic by fear and mistrust in government. This study aims to depict different profiles and characteristics of people reluctant to vaccinate, focusing on the drivers of those who are in favor of and those who are opposed to receiving the COVID-19 vaccine. METHODS: A sample of 10,000 Italian residents was collected. A survey on COVID-19 vaccination behavior and possible determinants of vaccine uptake, delay, and refusal was administered to participants through a computer-assisted web interviewing method. RESULTS: In our sample, 83.2% stated that they were vaccinated as soon as possible ("vaccinators"), 8.0% delayed vaccination ("delayers"), and 6.7% refused to be vaccinated ("no-vaccinators"). In general, the results show that being female, aged between 25 and 64, with an education level less than a high school diploma or above a master's degree, and coming from a rural area were characteristics significantly associated with delaying or refusing COVID-19 vaccination. In addition, it was found that having minimal trust in science and/or government (i.e., 1 or 2 points on a scale from 1 to 10), using alternative medicine as the main source of treatment, and intention to vote for certain parties were characteristics associated with profiles of "delayers" or "no-vaccinators". Finally, the main reported motivation for delaying or not accepting vaccination was fear of vaccine side effects (55.0% among delayers, 55.6% among no-vaccinators). CONCLUSION: In this study, three main profiles of those who chose to be vaccinated are described. Since those who are in favor of vaccines and those who are not usually cluster in similar sociodemographic categories, we argue that findings from this study might be useful to policy makers when shaping vaccine strategies and choosing policy instruments.

7.
Carbohydr Polym ; 311: 120745, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37028873

RESUMO

Alginate-based hydrogels with tunable mechanical properties are developed by chemical methylation of the polysaccharide backbone, which was performed either in homogeneous phase (in solution) or in heterogeneous phase (on hydrogels). Nuclear Magnetic Resonance (NMR) and Size Exclusion Chromatography (SEC-MALS) analyses of methylated alginates allow to identify the presence and location of methyl groups on the polysaccharide, and to investigate the influence of methylation on the stiffness of the polymer chains. The methylated polysaccharides are employed for the manufacturing of calcium-reticulated hydrogels for cell growth in 3D. The rheological characterization shows that the shear modulus of hydrogels is dependent on the amount of cross-linker used. Methylated alginates represent a platform to explore the effect of mechanical properties on cell activity. As an example, the effect of compliance is investigated using hydrogels displaying similar shear modulus. An osteosarcoma cell line (MG-63) was encapsulated in the alginate hydrogels and the effect of material compliance on cell proliferation and localization of YAP/TAZ protein complex is investigated by flow cytometry and immunohistochemistry, respectively. The results point out that an increase of material compliance leads to an increase of the proliferative rate of cells and correlates with the translocation of YAP/TAZ inside the cell nucleus.


Assuntos
Alginatos , Hidrogéis , Alginatos/química , Hidrogéis/química , Linhagem Celular
8.
Behav Sci (Basel) ; 13(2)2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36829343

RESUMO

Regular physical activity (PA) is protective and reduces disease burden but remains a challenge for pregnant women (PW). According to the World Health Organization (WHO) guidelines, PW without contraindications should practice 150 min of moderate PA per week. Nonetheless, PA levels are concerningly low among PW. The aim of this study was to investigate PW's and midwives' perceptions regarding PA and recommended guidelines, and use this information to inform future health promotion strategies. We recruited 10 PW and 10 midwives to participate in online focus groups conducted between July 2020 and April 2021. Focus group probes and data analysis were guided by the COM-B (capability, opportunity, motivation-behaviour) framework. The majority of the sample had already practised PA, recognized the importance of PA during pregnancy, and considered the WHO guidelines reasonable. Notwithstanding, PW wanted more specific instruction on PA and desired opportunities to practice. Additional barriers reported by PW included low self-efficacy and lack of motivation. Midwives considered the lack of specific knowledge and confidence in managing PA as the main obstacles. The current findings suggest that PW and midwives need specific training in PA to overcome both psychological and physical barriers. Midwives play a vital role in educating and encouraging PA among PW.

9.
Carbohydr Polym ; 302: 120369, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36604049

RESUMO

In vitro studies of mesenchymal stem cells (MSCs) differentiation have been predominantly performed with non-physiologically elastic materials. Here we report the effect of different viscoplastic ECM mimics on the osteogenic engagement of MSCs in 2D. We have developed soft hydrogels, composed of a lactose-modified chitosan, using a combination of permanent and temporary cross-links. The presence of temporary cross-links has a minor effect on the shear modulus of the hydrogels, but causes an immediate relaxation (dissipation) of the applied stress. This material property leads to early osteogenic commitment of MSCs, as evidenced by gene expression of runt-related transcription factor 2 (RUNX2), type 1 collagen (COL1A1), osteocalcin (OCN), alkaline phosphatase enzyme activity (ALP) and calcium deposit formation. In contrast, cells cultured on purely elastic hydrogels with only permanent cross-link begin to differentiate only after a longer period of time, indicating a dissipation-mediated mechano-sensing in the osteogenic commitment of MSCs.


Assuntos
Hidrogéis , Células-Tronco Mesenquimais , Hidrogéis/farmacologia , Hidrogéis/metabolismo , Células Cultivadas , Osteogênese , Diferenciação Celular
10.
Vaccines (Basel) ; 10(4)2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35455300

RESUMO

Infectious diseases have always posed a significant threat to mankind, resulting in high mortality and morbidity throughout history [...].

11.
Vaccines (Basel) ; 10(3)2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35335007

RESUMO

In the context of an ageing population, one of the major Public Health goals is to promote healthy ageing. To rise to this challenge, rethinking conventional prevention paradigms and implementing them with vaccination at all stages of life is necessary. Indeed, vaccinations are able to both prevent pathogen specific diseases and all their downstream effects and to increase overall immune system plasticity and resilience. Our aim is to discuss the obstacles and opportunities in pursuing a "life-course vaccination approach" and to highlight the role of vaccines in healthy ageing. In doing so, we address the close connections between immunology and vaccinology advances and introduce the novel concept of immune fitness. Finally, we conclude that even though vaccinology is making giant steps towards tailored vaccination strategies, more studies are needed to investigate this topic.

12.
Int J Mol Sci ; 21(18)2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32957651

RESUMO

The present manuscript deals with the elucidation of the mechanism of genipin binding by primary amines at neutral pH. UV-VIS and CD measurements both in the presence of oxygen and in oxygen-depleted conditions, combined with computational analyses, led to propose a novel mechanism for the formation of genipin derivatives. The indications collected with chiral and achiral primary amines allowed interpreting the genipin binding to a lactose-modified chitosan (CTL or Chitlac), which is soluble at all pH values. Two types of reaction and their kinetics were found in the presence of oxygen: (i) an interchain reticulation, which involves two genipin molecules and two polysaccharide chains, and (ii) a binding of one genipin molecule to the polymer chain without chain-chain reticulation. The latter evolves in additional interchain cross-links, leading to the formation of the well-known blue iridoid-derivatives.


Assuntos
Quitosana/química , Iridoides/química , Lactose/química , Aminas/química , Materiais Biocompatíveis/química , Quitosana/análogos & derivados , Quitosana/síntese química , Dicroísmo Circular , Química Computacional , Reagentes de Ligações Cruzadas/química , Concentração de Íons de Hidrogênio , Cinética , Ligantes , Espectroscopia de Ressonância Magnética , Oxigênio/química , Polissacarídeos/química , Espectrofotometria Ultravioleta
13.
Front Vet Sci ; 7: 369, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32850991

RESUMO

Host specificity plays one of the key roles in parasitism. It affects the evolution and diversification of both host and parasite, as well as it influences their geographical distribution, and epidemiological significance. For most of parasites, however, host specificity is unknown or misrepresented because it is difficult to be determined accurately. Here we provide the information about the lower host specificity of Eimeria sciurorum infecting squirrels, and its new host record for the Calabrian black squirrel Sciurus meridionalis, a southern Italian endemic species.

14.
Molecules ; 25(7)2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32230971

RESUMO

Chitosan derivatives, and more specifically, glycosylated derivatives, are nowadays attracting much attention within the scientific community due to the fact that this set of engineered polysaccharides finds application in different sectors, spanning from food to the biomedical field. Overcoming chitosan (physical) limitations or grafting biological relevant molecules, to mention a few, represent two cardinal strategies to modify parent biopolymer; thereby, synthetizing high added value polysaccharides. The present review is focused on the introduction of oligosaccharide side chains on the backbone of chitosan. The synthetic aspects and the effect on physical-chemical properties of such modifications are discussed. Finally, examples of potential applications in biomaterials design and drug delivery of these novel modified chitosans are disclosed.


Assuntos
Materiais Biocompatíveis/química , Quitosana/química , Sistemas de Liberação de Medicamentos/métodos , Oligossacarídeos/química , Engenharia Tecidual/métodos , Animais , Quitosana/análogos & derivados , Quitosana/síntese química , Glicosilação , Humanos , Simulação de Dinâmica Molecular , Nanopartículas/química
15.
J Biomed Mater Res A ; 108(7): 1534-1545, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32170901

RESUMO

Biodegradable membranes for cartilage applications were manufactured starting from polymeric networks of a lactose-modified chitosan (CTL), previously proposed for chondrocytes stimulation. This implantable biomaterial was conceived as a reservoir of a bioactive polymer that could promote the activity of chondrocytes and the healing of cartilage defects. Freeze-drying of reticulated hydrogels enabled to obtain pliable membranes with a homogeneous polymeric texture, as pointed out by scanning electron microscopy analyses. Swelling tests and dimensional evaluations showed that the material is able to absorb physiological fluids and expand gradually upon rehydration. This feature was evaluated on a simulated cartilage defect on pig's humerus (ex vivo), which revealed the capability of the membranes to progressively fit the tissue voids on the damaged cartilage. The rheological properties of the rehydrated membranes pointed out their peculiar strain-stiffening behavior, which represents a promising feature for the regeneration of tissues subjected to variable mechanical loads and deformations. Biological in vitro studies demonstrated the biocompatibility of the membranes in contact with primary chondrocytes and osteoblasts. Taken together, these results represent a starting point for the development of a novel generation of implantable biomaterials for cartilage treatment based on CTL.


Assuntos
Implantes Absorvíveis , Materiais Biocompatíveis/química , Cartilagem Articular/lesões , Quitosana/análogos & derivados , Condrócitos/citologia , Animais , Células Cultivadas , Suínos
16.
J Mater Sci Mater Med ; 30(6): 60, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31127386

RESUMO

Implantable membranes based on alginate and hyaluronic acid (HA) were manufactured to obtain a rapidly resorbing pliable mesh for the in situ administration of HA to intestinal tissue. Morphological analyses of this interpenetrated matrix pointed out a homogeneous polymeric texture while degradation studies demonstrated that the material is able to dissolve in physiological solutions within few days. Biological studies in vitro showed that the membrane is biocompatible towards human dermal fibroblasts and that liquid extracts from the HA-containing membrane can stimulate wound healing. A preliminary in vivo biocompatibility study on rats showed that the membranes in direct contact with the intestine did not elicit any acute adverse reaction or immune response, while only a mild inflammatory reaction was noticed at the mesenteric or serosal region. Overall, these results appear to support the application of these polysaccharide-based materials for intestinal wound healing.


Assuntos
Materiais Biocompatíveis/química , Ácido Hialurônico/química , Ferida Cirúrgica/terapia , Cicatrização , Alginatos/química , Animais , Sobrevivência Celular , Fibroblastos/metabolismo , Ácidos Hexurônicos/química , Humanos , Inflamação , Teste de Materiais , Camundongos , Células NIH 3T3 , Polímeros , Polissacarídeos/química , Ratos , Pele/metabolismo
17.
Carbohydr Polym ; 208: 451-456, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30658823

RESUMO

Developing synthetic materials able to mimic micro- and macrorheological properties of natural networks opens up to novel applications and concepts in materials science. The present contribution describes an active network based on a semi-synthetic polymer, a lactitol-bearing chitosan derivative (Chitlac), and a transient inorganic cross-linker, boric acid. Due to the many and diverse anchoring points for boric acid on the flanking groups of Chitlac, the cross-links constantly break and reform in a highly dynamic fashion. The consequence is a network with unusual non-equilibrium and mechanical properties closely resembling the rheological behavior of natural three-dimensional arrangements and of cytoskeleton. Concepts like network nucleation, reorganization and disassembly are declined in terms of amount of the cross-linker, which acts as a putative motor for remodeling of the network upon application of energy. The out-of-equilibrium and non-linear behavior render the semi-synthetic system of great interest for tissue engineering and for developing in-vitro mimics of natural active matrices.


Assuntos
Materiais Biocompatíveis/química , Quitosana/química , Lactose/química , Ácidos Bóricos/química , Difusão Dinâmica da Luz , Reologia
18.
Clin Case Rep ; 5(12): 1988-1991, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29225841

RESUMO

Patients with advanced variants of Systemic Mastocytosis may develop destructive bone lesions when massive mast cell (MC) infiltrates are present. Finding of large osteolyses in indolent systemic mastocytosis, typically characterized by low MC burden, should prompt investigations for an alternative explanation.

19.
Colloids Surf B Biointerfaces ; 155: 553-559, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28499217

RESUMO

Adhesive coatings for implantable biomaterials can be designed to prevent material displacement from the site of implant. In this paper, a strategy based on the use of melanin-like nanoparticles (MNPs) for the development of adhesive coatings for polysaccharidic membranes was devised. MNPs were synthesized in vitro and characterized in terms of dimensions and surface potential, as a function of pH and ionic strength. The in vitro biocompatibility of MNPs was investigated on fibroblast cells, while the antimicrobial properties of MNPs in suspension were evaluated on E. coli and S. aureus cultures. The manufacturing of the adhesive coatings was carried out by spreading MNPs over the surface of polysaccharidic membranes; the adhesive properties of the nano-engineered coating to the target tissue (intestinal serosa) were studied in simulated physiological conditions. Overall, this study opens for novel approaches in the design of naturally inspired nanostructured adhesive systems.


Assuntos
Adesivos/química , Materiais Revestidos Biocompatíveis/química , Melaninas/química , Nanopartículas/química , Adulto , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Materiais Revestidos Biocompatíveis/síntese química , Materiais Revestidos Biocompatíveis/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/ultraestrutura , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Membranas/efeitos dos fármacos , Membranas/metabolismo , Membranas/ultraestrutura , Microscopia Eletrônica de Varredura , Nanopartículas/ultraestrutura , Polissacarídeos/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/ultraestrutura
20.
Int J Biol Macromol ; 95: 49-53, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27845225

RESUMO

The manuscript focuses on the demixing of hyaluronan and alginate in the hydrogel state. Binary solutions of the two polysaccharides have been treated with Ca2+ as the alginate cross-linking ion and the radial distribution of the two components in the hydrogels was measured by means of 1H NMR. These results revealed the presence of alginate-enriched and hyaluronan-enriched domains stemming from a polysaccharide demixing. The hydrogels were characterized by means of uniaxial compression and creep-compliance measurements which showed that the demixing increased the overall resistance of the hydrogel to stress. In addition, due to the viscoelastic properties of hyaluronan, a marked increase of the Newtonian viscosity of the constructs was noticed. The peculiarity of the effect of hyaluronan was demonstrated by the use of an alginate unable to form gel by binding non-calcium binding alginate, i.e. mannuronan, ruling out the effect of viscosity over the time-dependent behavior of the mixed hyaluronan-alginate hydrogels.


Assuntos
Alginatos/química , Ácido Hialurônico/química , Materiais Biocompatíveis/química , Géis , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Fenômenos Mecânicos
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