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Skin disorders are widespread around the world, affecting people of all ages, and oxidative stress represents one of the main causes of alteration in the normal physiological parameters of skin cells. In this work, we combined a natural protein, fibroin, with antioxidant compounds extracted in water from pomegranate waste. We demonstrate the effective and facile fabrication of bioactive and eco-sustainable films of potential interest for skin repair. The blended films are visually transparent (around 90%); flexible; stable in physiological conditions and in the presence of trypsin for 12 days; able to release the bioactive compounds in a controlled manner; based on Fickian diffusion; and biocompatible towards the main skin cells, keratinocytes and fibroblasts. Furthermore, reactive oxygen species (ROS) production tests demonstrated the high capacity of our films to reduce the oxidative stress induced in cells, which is responsible for various skin diseases.
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Fibroínas , Punica granatum , Fibroblastos , Humanos , Queratinócitos , SedaRESUMO
Histone deacetylases, HDACs, have been demonstrated to play a critical role in epigenetic signaling and were found to be overexpressed in several type of cancers; therefore, they represent valuable targets for anticancer therapy. 9-Hydroxystearic acid has been shown to bind the catalytic site of HDAC1, inducing G0/G1 phase cell cycle arrest and activation of the p21WAF1 gene, thus promoting cell growth inhibition and differentiation in many cancer cells. Despite the ( R) enantiomer of 9-hydroxystearic acid (9R) displaying a promising in vitro growth-inhibitory effect on the HT29 cell line, its scarce water solubility and micromolar activity require novel solutions for improving its efficacy and bioavailability. In this work, we describe the synthesis and in vitro biological profiling of 9R keratin nanoparticles (9R@ker) obtained through an in-water drug-induced aggregation process. The anticancer activity of 9R@ker was investigated in the HT29 cell line; the results indicate an increased fluidity of cell membrane and a higher intracellular ROS formation, resulting in an unexpected S phase cell cycle arrest (25% increase as compared to the control) induced by 9R@ker with respect to free 9R and an induction of cell death.
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Adenocarcinoma/patologia , Neoplasias do Colo/patologia , Descoberta de Drogas/métodos , Queratinas/química , Nanopartículas/química , Pontos de Checagem da Fase S do Ciclo Celular/efeitos dos fármacos , Ácidos Esteáricos/química , Albuminas/química , Membrana Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Química Sintética/métodos , Células HCT116 , Células HT29 , Histona Desacetilase 1/antagonistas & inibidores , Humanos , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Solubilidade , Ácidos Esteáricos/farmacologiaRESUMO
Photoactivatable keratin sponges were prepared from protein aqueous solutions by the freeze-drying method, followed by photofunctionalization with two different photosensitizers (PS): Azure A (AzA) and 5,10,15,20-tetrakis [4-(2-N,N,N-trimethylethylthio)-2,3,5,6-tetrafluorophenyl]porphyrin tetraiodide salt (TTFAP). The prepared sponges have a porosity between 49% and 80% and a mean pore size in the 37-80 µm range. As compared to AzA, TTFAP interacts more strongly with the sponges as demonstrated by a lower PS release (6% vs 20%), a decreased swelling ratio (1.6 vs 7.4), and a slower biodegradation rate. Nevertheless, AzA-loaded sponges showed the highest photoactivity, as also demonstrated by their higher antibactericidal activity toward both Gram-positive and Gram-negative bacteria. The obtained results suggest that the antimicrobial photodynamic effect can be finely triggered through a proper selection of the amount and type of photosensitizer, as well as through the irradiation time. Finally, all the prepared sponges support human fibroblast cells growth, while no significant cell viability impairment is observed upon light irradiation.
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Anti-Infecciosos/farmacologia , Queratinas/química , Queratinas/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Lã/química , Animais , Anti-Infecciosos/química , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Células Cultivadas , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/efeitos da radiação , Humanos , Luz , Pseudomonas aeruginosa/efeitos da radiação , Staphylococcus aureus/efeitos da radiaçãoRESUMO
The valorization of discarded wool from dairy sheep breeding is a challenging issue. The most proposed strategies lie in the processing of keratin extracted from wool without reducing the molecular weight of the protein chains (the high molecular weight-HMW keratin). Here, the HMW keratin has been spun for the first time by solution blow spinning. A screening study of the process carried out with a 2-level full factorial design revealed that keratin filaments can be obtained by using the polyethylene oxide at 900 kDa, a 2 bar air pressure, and a 30 cm needle-collector distance. An annealing at 80 °C for 15 min, at pH 3.5 with citric acid contributes to increasing the viscosity of the keratin solutions thereby allowing the production of defect-free and water-stable filaments having diameters from 1 to 6 µm. A negligible toxic effect was observed after 24 and 48 h on HT29 epithelial cells and normal blood cells displayed behavior similar to the control demonstrating that the patches are hemocompatible. Therefore, the developed SBS process of keratin aqueous solutions could represent a valuable platform for developing patches that need to be blood-contacting and deposited in-situ.
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Queratinas , Lã , Queratinas/química , Animais , Lã/química , Ovinos , Humanos , Peso Molecular , SoluçõesRESUMO
The future of biomaterial production will leverage biotechnology based on the domestication of cells as biological factories. Plants, algae, and bacteria can produce low-environmental impact biopolymers. Here, two strategies were developed to produce a biopolymer derived from a bioengineered vacuolar storage protein of the common bean (phaseolin; PHSL). The cys-added PHSL* forms linear-structured biopolymers when expressed in the thylakoids of transplastomic tobacco leaves by exploiting the formation of inter-chain disulfide bridges. The same protein without signal peptide (ΔPHSL*) accumulates in Escherichia coli inclusion bodies as high-molar-mass species polymers that can subsequently be oxidized to form disulfide crosslinking bridges in order to increase the stiffness of the biomaterial, a valid alternative to the use of chemical crosslinkers. The E. coli cells produced 300 times more engineered PHSL, measured as percentage of total soluble proteins, than transplastomic tobacco plants. Moreover, the thiol groups of cysteine allow the site-specific PEGylation of ΔPHSL*, which is a desirable functionality in the design of a protein-based drug carrier. In conclusion, ΔPHSL* expressed in E. coli has the potential to become an innovative biopolymer.
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Biotecnologia , Escherichia coli , Escherichia coli/genética , Plantas , Biopolímeros , Nicotiana/genética , Dissulfetos , Materiais BiocompatíveisRESUMO
In recent years, 3D printing has attracted great interest in the pharmaceutical field as a promising tool for the on-demand manufacturing of patient-centered pharmaceutical forms. Among the existing 3D printing techniques, direct powder extrusion (DPE) resulted as the most practical approach thanks to the possibility to directly process excipients and drugs in a single step. The main goal of this work was to determine whether different grades of ethylene vinyl acetate (EVA) copolymer might be employed as new feedstock materials for the DPE technique to manufacture transdermal patches. By selecting two model drugs with different thermal behavior, (i.e., ibuprofen and diclofenac sodium) we also wanted to pay attention to the versatility of EVA excipient in preparing patches for customized transdermal therapies. EVA was combined with 30 % (w/w) of each model drugs. The physicochemical composition of the printed devices was investigated through Fourier-transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analyses. FT-IR spectra confirmed that the starting materials were effectively incorporated into the final formulation, and thermal analyses demonstrated that the extrusion process altered the crystalline morphology of the raw polymers inducing the formation of crystals at lower thicknesses. Lastly, the drug release and permeation profile of the printed systems was evaluated for 48 h and showed to be dependent on the VA content of the EVA grade (74.5 % of ibuprofen released from EVA 4030AC matrix and 12.6 % of diclofenac sodium released from EVA1821A matrix). Hence, this study demonstrated that EVA and direct powder extrusion technique could be promising tools for manufacturing transdermal patches. By selecting the EVA grade with the appropriate VA content, drugs with dissimilar melting points could be printed preserving their thermal stability. Moreover, the desired drug release and permeation profile of the drug can be achieved, representing an important advantage in terms of personalized medicine.
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Diclofenaco , Ibuprofeno , Humanos , Pós , Espectroscopia de Infravermelho com Transformada de Fourier , Liberação Controlada de Fármacos , Impressão Tridimensional , ComprimidosRESUMO
Fungal infections of the skin, nails, and hair are a common health concern affecting a significant proportion of the population worldwide. The current treatment options include topical and systematic agents which have low permeability and prolonged treatment period, respectively. Consequently, there is a growing need for a permeable, effective, and safe treatment. Keratin nanoparticles are a promising nanoformulation that can improve antifungal agent penetration, providing sustainable targeted drug delivery. In this study, keratin nanoparticles were prepared using a custom-made 3D-printed microfluidic chip and the manufacturing process was optimized using the design of experiments (DoE) approach. The total flow rate (TFR), flow rate ratio (FRR), and keratin concentration were found to be the most influential factors of the size and polydispersity index (PDI) of the nanoparticles. The crosslinking procedure by means of tannic acid as safe and biocompatible compound was also optimized. Keratin nanoparticles loaded with a different amount of tioconazole showed a size lower than 200 nm, a PDI lower than 0.2 and an encapsulation efficiency of 91 ± 1.9 %. Due to their sustained drug release, the formulations showed acceptable in vitro biocompatibility. Furthermore, a significant inhibitory effect compared to the free drug against Microsporum canis.
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Microfluídica , Nanopartículas , Microfluídica/métodos , Queratinas , Sistemas de Liberação de Medicamentos/métodos , Imidazóis , Tamanho da PartículaRESUMO
Here, we present novel biocompatible poly(butylene trans-1,4-cyclohexanedicarboxylate) (PBCE)-based random copolymer nanostructured scaffolds with tailored stiffness and hydrophilicity. The introduction of a butylene diglycolate (BDG) co-unit, containing ether oxygen atoms, along the PBCE chain remarkably improved the hydrophilicity and chain flexibility. The copolymer containing 50 mol% BDG co-units (BDG50) and the parent homopolymer (PBCE) were synthesized and processed as electrospun scaffolds and compression-molded films, added for the sake of comparison. We performed thermal, wettability, and stress-strain measures on the PBCE-derived scaffolds and films. We also conducted biocompatibility studies by evaluating the adhesion and proliferation of multipotent mesenchymal/stromal cells (hBM-MSCs) on each polymeric film and scaffold. We demonstrated that solid-state properties can be tailored by altering sample morphology besides chemical structure. Thus, scaffolds were characterized by a higher hydrophobicity and a lower elastic modulus than the corresponding films. The three-dimensional nanostructure conferred a higher adsorption protein capability to the scaffolds compared to their film counterparts. Finally, the PBCE and BDG50 scaffolds were suitable for the long-term culture of hBM-MSCs. Collectively, the PBCE homopolymer and copolymer are good candidates for tissue engineering applications.
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Cardiac tissue engineering is a cutting-edge technology aiming to replace irreversibly damaged cardiac tissue and restore contractile functionality. However, cardiac tissue engineering porous and perfusable scaffolds to enable oxygen supply in vitro and eventually promote angiogenesis in vivo are still desirable. Two fully-aliphatic random copolymers of poly(butylene succinate) (PBS), poly(butylene succinate/Pripol), P(BSBPripol), and poly(butylene/neopentyl glycol succinate), P(BSNS), containing two different subunits, neopentyl glycol and Pripol 1009, were successfully synthesized and then electrospun in tridimentional fibrous mats. The copolymers show different thermal and mechanical behaviours as result of their chemical structure. In particular, copolymerization led to a reduction in crystallinity and consequently PBS stiffness, reaching values of elastic modulus very close to those of soft tissues. Then, to check the biological suitability, human induced Pluripotent Stem Cells (hiPSCs) were directly seeded on both PBS-based copolymeric scaffolds. The results confirmed the ability of both the scaffolds to sustain cell viability and to maintain their stemness during cell expansion. Furthermore, gene expression and immunofluorescence analysis showed that P(BSBPripol) scaffold promoted an upregulation of the early cardiac progenitor and later-stage markers with a simultaneously upregulation of HYPPO pathway gene expression, crucial for mechanosensing of cardiac progenitor cells. These results suggest that the correct ad-hoc chemical design and, in turn, the mechanical properties of the matrix, such as substrate stiffness, together with surface porosity, play a critical role in regulating the behaviour of cardiac progenitors, which ultimately offers valuable insights into the development of novel bio-inspired scaffolds for cardiac tissue regeneration.
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Células-Tronco Pluripotentes Induzidas , Alicerces Teciduais , Humanos , Alicerces Teciduais/química , Diferenciação Celular/genética , SuccinatosRESUMO
The delivery of therapeutics across biological membranes (e.g., mucosal barriers) by avoiding invasive routes (e.g., injection) remains a challenge in the pharmaceutical field. As such, there is the need to discover new compounds that act as drug permeability enhancers with a favorable toxicological profile. A valid alternative is represented by the class of sugar-based ester surfactants. In this study, sucrose and lactose alkyl aromatic and aromatic ester derivatives have been synthesized with the aim to characterize them in terms of their physicochemical properties, structure-property relationship, and cytotoxicity, and to test their ability as permeability enhancer agents across Calu-3 cells. All of the tested surfactants showed no remarkable cytotoxic effect on Calu-3 cells when applied both below and above their critical micelle concentration. Among the explored molecules, lactose p-biphenyl benzoate (URB1420) and sucrose p-phenyl benzoate (URB1481) cause a reversible ~30% decrease in transepithelial electrical resistance (TEER) with the respect to the basal value. The obtained result matches with the increased in vitro permeability coefficients (Papp) calculated for FTIC-dextran across Calu-3 cells in the presence of 4 mM solutions of these surfactants. Overall, this study proposes sucrose- and lactose-based alkyl aromatic and aromatic ester surfactants as novel potential and safe permeation enhancers for pharmaceutical applications.
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Respiratory tract infections (RTIs) are reported to be the leading cause of death worldwide. Delivery of liposomal antibiotic nano-systems via the inhalation route has drawn significant interest in RTIs treatment as it can directly target the site of infection and reduces the risk of systemic exposure and side effects. Moreover, this formulation system can improve pharmacokinetics and biodistribution and enhance the activity against intracellular pathogens. Microfluidics is an innovative manufacturing technology that can produce nanomedicines in a homogenous and scalable way. The objective of this study was to evaluate the antibiofilm efficacy of two liposomal ciprofloxacin formulations with different vesicle sizes manufactured by using a 3D-printed microfluidic chip. Each formulation was characterised in terms of size, polydispersity index, charge and encapsulation. Moreover, the aerosolisation characteristics of the liposomal formulations were investigated and compared with free ciprofloxacin solution using laser diffraction and cascade impaction methods. The in vitro drug release was tested using the dialysis bag method. Furthermore, the drug transport and drug release studies were conducted using the alveolar epithelial H441 cell line integrated next-generation impactor in vitro model. Finally, the biofilm eradication efficacy was evaluated using a dual-chamber microfluidic in vitro model. Results showed that both liposomal-loaded ciprofloxacin formulations and free ciprofloxacin solution had comparable aerosolisation characteristics and biofilm-killing efficacy. The liposomal ciprofloxacin formulation of smaller vesicle size showed significantly slower drug release in the dialysis bag technique compared to the free ciprofloxacin solution. Interestingly, liposomal ciprofloxacin formulations successfully controlled the release of the drug in the epithelial cell model and showed different drug transport profiles on H441 cell lines compared to the free ciprofloxacin solution, supporting the potential for inhaled liposomal ciprofloxacin to provide a promising treatment for respiratory infections.
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Ciprofloxacina , Microfluídica , Distribuição Tecidual , Antibacterianos , LipossomosRESUMO
In this study, nanofibre mats for chemical adsorption of heavy metals were prepared by electrospinning blends of hydrolyzed keratin (HK) and polyamide 6 (PA6) in formic acid. Viscosity measurements of the spinning solutions and morphological analyses of the fracture sections of the same polymer blends cast into films, suggested intermolecular interactions and good compatibility between HK and PA6. The mats made of continuous randomly oriented blend nanofilaments of HK/PA6 50/50 wt, with a mean diameter of about 200 nm, were tested as chromium (VI) ion adsorbents. The parameters investigated included initial chromium ion concentration, pH, contact time and adsorbent dosage. The maximum adsorption capacity occurred at acidic pH. The pseudo-first order, the pseudo-second order and the intraparticle diffusion models were used to describe the kinetics of adsorption process. It was found that kinetic data fit the pseudo-second order model and follow the intraparticle diffusion model, although diffusion is not the only rate control step. Adsorption data fit well the Freundlich isotherm model and the maximum adsorption capacity was found 55.9 mg/g. Moreover, the mean free energy (E) of adsorption ranges between 8 and 16 kJ/mol, so that the adsorption mechanism for HK-based nanofibres was explained as an ion-exchange process.
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During the past decades, 3D printing has revolutionised different areas of research. Despite the considerable progress achieved in 3D printing of pharmaceuticals, the limited choice of suitable materials remains a challenge to overcome. The growing search for sustainable excipients has led to an increasing interest in biopolymers. Poly(3-hydroxybutyrate) (PHB) is a biocompatible and biodegradable biopolymer obtained from bacteria that could be efficiently employed in the pharmaceutical field. Here we aimed to demonstrate its potential application as a thermoplastic material for personalised medicine through 3D printing. More specifically, we processed PHB by using direct powder extrusion, a one-step additive manufacturing technique. To assess and denote the feasibility and versatility of the process, a 3D square model was manufactured in different dimensions (sidexheight: 12x2 mm; 18x2 mm; 24x2 mm) and loaded with increasing percentages of a model drug (up to 30% w/w). The manufacturing process was influenced by the drug content, and indeed, an increase in the amount of the drug determined a reduction in the printing temperature, without affecting the other parameters (such as the layer height). The composition of the model squares was investigated using Fourier-transform infrared spectroscopy, the resulting spectra confirmed that the starting materials were successfully incorporated into the final formulations. The thermal behaviour of the printed systems was characterized by differential scanning calorimetry, and thermal gravimetric analysis. Moreover, the sustained drug release profile of the formulations was performed over 21 days and showed to be dependent on the dimensions of the printed object and on the amount of loaded drug. Indeed, the formulation with 30% w/w in the dimension 24x2 mm released the highest amount of drug. Hence, the results suggested that PHB and direct powder extrusion technique could be promising tools for the manufacturing of prolonged release and personalised drug delivery forms.
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Excipientes , Tecnologia Farmacêutica , Ácido 3-Hidroxibutírico , Liberação Controlada de Fármacos , Excipientes/química , Hidroxibutiratos , Preparações Farmacêuticas , Poliésteres , Pós , Impressão Tridimensional , Comprimidos/química , Tecnologia Farmacêutica/métodosRESUMO
High-resolution ultrasound spectroscopy (HR-US) is a spectroscopic technique using ultrasound waves at high frequencies to investigate the structural properties of dispersed materials. This technique is able to monitor the variation of ultrasound parameters (sound speed and attenuation) due to the interaction of ultrasound waves with samples as a function of temperature and concentration. Despite being employed for the characterization of several colloidal systems, there is a lack in the literature regarding the comparison between the potential of HR-US for the determination of phospholipid thermal transitions and that of other common techniques both for loaded or unloaded liposomes. Thermal transitions of liposomes composed of pure phospholipids (dimyristoylphosphatidylcholine, DMPC; dipalmitoylphosphatidylcholine, DPPC and distearoylphosphatidylcholine, DSPC), cholesterol and their mixtures were investigated by HR-US in comparison to the most commonly employed microcalorimetry (mDSC) and dynamic light scattering (DLS). Moreover, tramadol hydrochloride, caffeine or miconazole nitrate as model drugs were loaded in DPPC liposomes to study the effect of their incorporation on thermal properties of a phospholipid bilayer. HR-US provided the determination of phospholipid sol-gel transition temperatures from both attenuation and sound speed that are comparable to those calculated by mDSC and DLS techniques for all analysed liposomal dispersions, both loaded and unloaded. Therefore, HR-US is proposed here as an alternative technique to determine the transition temperature of phospholipid membrane in liposomes.
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In recent years, several studies have focused their attention on the preparation of biocompatible and biodegradable nanocarriers of potential interest in the biomedical field, ranging from drug delivery systems to imaging and diagnosis. In this regard, natural biomolecules-such as proteins-represent an attractive alternative to synthetic polymers or inorganic materials, thanks to their numerous advantages, such as biocompatibility, biodegradability, and low immunogenicity. Among the most interesting proteins, keratin extracted from wool and feathers, as well as fibroin extracted from Bombyx mori cocoons, possess all of the abovementioned features required for biomedical applications. In the present review, we therefore aim to give an overview of the most important and efficient methodologies for obtaining drug-loaded keratin and fibroin nanoparticles, and of their potential for biomedical applications.
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Developing targeted drug delivery systems is an urgent need to decrease the side effects and increase the drug's efficiency. Most cancer cells show an increased sugar consumption compared to healthy cells due to the deregulation of sugar transporters. Consequently, liposomes, as a biocompatible nanocarrier, could be surface decorated by sugars to enhance drug targeting into cancer cells. Our work outlines a new strategy to easily manufacture sucrose decorated liposomes using sucrose stearate, a biocompatible and biodegradable non-ionic surfactant, with a scalable microfluidic approach. Sucrose decorated liposomes were loaded with berberine hydrochloride, a well-known phytochemical compound to investigate its effects on triple-negative breast cancer cells (MDA-MB-231). Using the microfluidic manufacturing system, we prepared berberine-loaded liposomes using a mixture of phosphatidylcholine and cholesterol with and without sucrose stearate with a size up to 140 nm and narrow polydispersity. Stability was confirmed for 90 days, and the in vitro release profile was evaluated. The formulations showed acceptable in vitro biocompatibility and significantly higher anti-proliferative effect on MDA-MB-231 cell line. These results have been confirmed by an increased uptake evaluated by flow cytometry and confocal microscopy. Taken together, our findings represent an innovative, easy, and scalable approach to obtain sugar decorated liposomal formulations without any surface-chemistry reactions. They can be potentially used as an anticancer targeted drug delivery system.
Assuntos
Berberina , Neoplasias de Mama Triplo Negativas , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos/métodos , Humanos , Lipossomos/química , Microfluídica , SacaroseRESUMO
In spite of an extensive body of academic initiatives and innovative products, the toolkit of wound dressing has always revolved around a few common concepts such as adhesive patches and stitches and their variants. Our work aims at an alternative solution for an immediate restitutio ad integrum of the mechanical functionality in cutaneous repairs. We describe the fabrication and the application of electrospun mats of bioactive nanofibers all made of biocompatible components such as a natural polysaccharide and a cyanine dye for use as laser-activatable plasters, resembling the ultrastructure of human dermis. In particular, we investigate their morphological features and mechanical moduli under conditions of physiological relevance, and we test their use to bind a frequent benchmark of connective tissue as rabbit tendon and a significant case of clinical relevance as human dermis. Altogether, our results point to the feasibility of a new material for wound dressing combining translational potential, strength close to human dermis, extensibility exceeding 15% and state-of-art adhesive properties.
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In this work keratin/poly(lactic acid) (PLA) 50/50 wt blend nanofibers with different loadings of graphene-oxide (GO) were prepared by electrospinning and tested as delivery systems of Rhodamine Blue (RhB), selected as a model of a drug. The effect of GO on the electrospinnability and drug release mechanism and kinetics was investigated. Rheological measurements carried out on the blend solutions revealed unsatisfactory compatibility between keratin and PLA under quiet condition. Accordingly, poor interfacial adhesion between the two phases was observed by SEM analysis of a film prepared by solution casting. On the contrary, keratin chains seem to rearrange under the flux conditions of the electrospinning process thus promoting better interfacial interactions between the two polymers, thereby enhancing their miscibility, which resulted in homogeneous and defect-free nanofibers. The loading of GO into the keratin/PLA solution contributes to increase its viscosity, its shear thinning behavior, and its conductivity. Accordingly, thinner and more homogeneous nanofibers resulted from solutions with a relatively high conductivity coupled with a pronounced shear thinning behavior. FTIR and DSC analyses have underlined, that while the PLA/GO interfacial interactions significantly compete with the PLA/keratin ones, there are no significant effects of GO on the structural organization of keratin in blend with the PLA. However, GO offers several advantages from the application point of view by slightly improving the mechanical properties of the electrospun mats and by slowing down the release of the model drug through the reduction of the matrix swelling.
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Grafite , Nanofibras , Grafite/química , Queratinas/química , Nanofibras/química , Poliésteres/químicaRESUMO
In recent years there has been a growing interest in the use of proteins as biocompatible and environmentally friendly biomolecules for the design of wound healing and drug delivery systems. Keratin is a fascinating protein, obtainable from several keratinous biomasses such as wool, hair or nails, with intrinsic bioactive properties including stimulatory effects on wound repair and excellent carrier capability. In this work keratin/poly(butylene succinate) blend solutions with functional properties tunable by manipulating the polymer blending ratios were prepared by using 1,1,1,3,3,3-hexafluoroisopropanol as common solvent. Afterwards, these solutions doped with rhodamine B (RhB), were electrospun into blend mats and the drug release mechanism and kinetics as a function of blend composition was studied, in order to understand the potential of such membranes as drug delivery systems. The electrophoresis analysis carried out on keratin revealed that the solvent used does not degrade the protein. Moreover, all the blend solutions showed a non-Newtonian behavior, among which the Keratin/PBS 70/30 and 30/70 ones showed an amplified orientation ability of the polymer chains when subjected to a shear stress. Therefore, the resulting nanofibers showed thinner mean diameters and narrower diameter distributions compared to the Keratin/PBS 50/50 blend solution. The thermal stability and the mechanical properties of the blend electrospun mats improved by increasing the PBS content. Finally, the RhB release rate increased by increasing the keratin content of the mats and the drug diffused as drug-protein complex.
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Butileno Glicóis/síntese química , Sistemas de Liberação de Medicamentos/métodos , Desenho de Fármacos , Liberação Controlada de Fármacos , Queratinas/síntese química , Nanofibras/química , Polímeros/síntese química , Animais , Butileno Glicóis/farmacocinética , Queratinas/farmacocinética , Polímeros/farmacocinéticaRESUMO
In this study, a bio-based polymeric system loaded with fruit by-products was developed. It was based on silk fibroin produced by the silkworm Bombyx mori and pomegranate peel powder, selected as active agent. The weight ratio between fibroin and pomegranate powder was 30:70. Pads also contained 20% w/w of glycerol vs. fibroin to induce water insolubility. Control systems, consisting of only fibroin and glycerol, were produced as reference. Both control and active systems were characterized for structural and morphological characterization (Fourier-transform infrared spectroscopy and optical microscope), antioxidant properties and antimicrobial activity against two foodborne spoilage microorganisms. Results demonstrate that under investigated conditions, an active system was obtained. The pad showed a good water stability, with weight loss of about 28% due to the release of the active agent and not to the fibroin loss. In addition, this edible system has interesting antioxidant and antimicrobial properties. In particular, the pad based on fibroin with pomegranate peel recorded an antioxidant activity of the same order of magnitude of that of vitamin C, which is one of the most well-known antioxidant compounds. As regards the antimicrobial properties, results underlined that pomegranate peel in the pad allowed maintaining microbial concentration around the same initial level (104 CFU/mL) for more than 70 h of monitoring, compared to the control system where viable cell concentration increased very rapidly up to 108 CFU/mL.