Recent advances in silk sericin/calcium phosphate biomaterials

Calcium phosphates (CaPs) have been widely used in the field of biomedical engineering as bone graft substitutes or as carriers for drug delivery applications. Recent developments have focused on combining CaPs with proteins to obtain functional biomaterials that accommodate a broader spectrum of functional requirements. Silk sericin was considered an unutilized protein by-product from the textile industry, generating tons of residues every year. However, much effort has been dedicated to its recovery after being associated with numerous biological properties such as antioxidant, antibacterial, anti-coagulation and regenerative activities. In the past years, sericin has also demonstrated to be suitable as a template for CaPmineralization. The present review focuses on the recent developments for the production of sericin/CaP composites, exploring their potential applications in bioengineering and opening new avenues in other research fields such as in the cosmetic, food and environmental sectors. In addition, this paper can also be useful as a guideline to design future research based on sericin/CaP biomaterials.info:eu-repo/semantics/publishedVersio

Fabrication of calcium phosphates with controlled properties using a modular oscillatory flow reactor

Several technologies and synthesis routes have been implemented to produce calcium phosphates (CaPs) with distinct characteristics for biomedical applications. However, produce CaPs in a controlled way still represents a challenge. Oscillatory flow reactors (OFRs) are a technology ready to deliver in terms of mixing intensification in multiphase systems. In particular, continuous processes in OFRs improve control over the reaction conditions and can be implemented at an industrial scale. The aim of this work was to study for the first time the influence of the oscillation amplitude (x0: 4, 8 and 18 mm) and frequency (f: 1.9, 4 and 6 Hz) as well as residence time (τ: 3.3, 6.6 min) on the final CaP particles’ physicochemical properties using a continuous precipitation process in a novel modular oscillatory flow plate reactor (MOFPR). Furthermore, other parameters such as the initial reagents concentration, initial Ca/P molar ratio (Ca/P = 1.67, 1.33) and temperature (T = 37, 54 ºC) were also assessed. The synthesized particles and overall process were compared with particles obtained using the same methodology in conventional reactors, evidencing the potential of this technology to fabricate CaPs with tailored properties for potential application as nano or microcarriers for biomedical applications.info:eu-repo/semantics/publishedVersio

Fabrication of highly tuned calciumphosphate/silk sericin composites: exploring new pathways on skin regeneration

info:eu-repo/semantics/publishedVersio

Continuous production of hydroxyapatite/sericin composites: and in vitro validation for skin regeneration

info:eu-repo/semantics/publishedVersio

Continuous-flow precipitation as a route to prepare highly controlled nanohydroxyapatite

[Excerpt] Hydroxyapatite Ca10(PO4)6(OH)2 (HAp) has been widely used for biomedical purposes because of its exceptional biocompatibility, bioactivity and osteoconductivity [1]. As these properties are directly related to HAp particles characteristics (size, morphology and purity), a very good control of the reaction conditions is required to obtain particles with the desired properties. Usually, HAp is synthesized by wet chemical precipitation in stirred tank batch reactors that often lead to inconsistencies in product specifications due to their low mixing efficiency [2]. (...

CdSe quantum dots using polyselenide precursor in soft chemical conditions

CdSe quantum dots were prepared by a simple microemulsion templating technique at low temperature and using common inorganic precursors. Size control was obtained by small variations in reactant concentrations. The chalcogenide source was a polyselenide solution. Narrow (30-40nm fwhm) band gap photoluminescence low defect level and high quantum yield were obtained.FCT and FEDER for financial support to the Research Centre, CFUM [PEst-C/FIS/UI0607/2011 (F-COMP-01-0124-FEDER-022711)] and to the research project PTDC/FIS/113199/200

Crystallization and preliminary structure determination of the membrane-bound complex cytochrome c nitrite reductase from Desulfovibrio vulgaris Hildenborough

The cytochrome c nitrite reductase (cNiR) isolated from Desulfovibrio vulgaris Hildenborough is a membrane-bound complex formed of NrfA and NrfH subunits. The catalytic subunit NrfA is a soluble pentahaem cytochrome c that forms a physiological dimer of about 120 kDa. The electron-donor subunit NrfH is a membrane-anchored tetrahaem cytochrome c of about 18 kDa molecular weight and belongs to the NapC/NirT family of quinol dehydrogenases, for which no structures are known. Crystals of the native cNiR membrane complex, solubilized with dodecylmaltoside detergent (DDM), were obtained using PEG 4K as precipitant. Anomalous diffraction data were measured at the Swiss Light Source to 2.3 Å resolution. Crystals belong to the orthorhombic space group P212121, with unit-cell parameters a = 79.5, b = 256.7, c = 578.2 Å. Molecular-replacement and MAD methods were combined to solve the structure. The data presented reveal that D. vulgaris cNiR contains one NrfH subunit per NrfA dimer.publishe

DROOd: desidratação de fruta e vegetais por ar seco

Apresenta-se um equipamento capaz de desidratar alimentos que poderá ser adquirido por pequenos agricultores. A proposta de um equipamento que consegue desidratar os produtos produzidos através de ar seco com uma potência equivalente à de um eletrodoméstico, 1,4 kW, tendo a capacidade de desidratar até 4 kg de frutas ou vegetais. Apresenta-se a simulação do funcionamento do equipamento a secar o equivalente a 23 tomates ou 24 bananas ou 21 laranjas simultaneamente distribuídos em 7 tabuleiros individuais, demorando 10, 8 e 9h, respetivamente, a serem desidratados.info:eu-repo/semantics/publishedVersio