An easy 3D printing approach to manufacture vertical diffusion cells for in vitro release and permeation studies

Vertical diffusion cells are commonly used in the pharmaceutical and cosmetic fields to study the release and permeation of active ingredients through synthetic or biological membranes. Nevertheless, the commercially available glass-based systems are expensive and need to be carefully handled due to their fragility. Fused deposition modeling 3D printing is an additive manufacturing technique that allows producing objects layer by layer using different thermoplastic materials. Among them, polypropylene is a robust, flexible, and chemically inert polymer that can resist to many organic solvents. In this work, we designed and printed a vertical diffusion cell following pharmacopeia requirements by using polypropylene in a fused deposition modeling 3D printer. To keep the system thermostated, the developed model fits in a heating block to avoid the use of water recirculating system. The vertical diffusion cells were leak-free and presented chemical resistance and no interaction with model molecules (i.e., caffeine, diclofenac sodium, and glycyrrhetinic acid). The 3D printed cells were compared to commercially available glass cells and then two different types of synthetic membranes (i.e., PDMS and Strat-M®) were used to evaluate the permeation of a caffeine hydrogel. The developed 3D printed testing system could represent an efficient alternative to the glass-based equipment

Keratin-based Nanofibres

Non

Poly(3-hydroxybutyrate): A potential biodegradable excipient for direct 3D printing of pharmaceuticals

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

Regenerated keratin membrane to match the in vitro drug diffusion through human epidermis

AbstractThis work aimed to develop membranes made of regenerated keratin and ceramides (CERs) to match the barrier property of the human stratum corneum in in vitro percutaneous absorption studies. The membrane composition was optimized on the basis of the in vitro drug diffusion profiles of ibuprofen, propranolol and testosterone chosen as model drugs on the basis of their different diffusion and solubility properties. The data were compared to those obtained using human epidermis.The ATR-FTIR and SEM analyses revealed that CERs were suspended into the regenerated keratin matrix, even if a partial solubilization occurred. It resulted in the membranes being physically stable after exposure to aqueous buffer and/or mineral oil and the fluxes of ibuprofen and propranolol from these vehicles through membranes and human skin were of the same order of magnitude. The best relationship with human epidermis data was obtained with 180μm-thick membrane containing 1% ceramide III and 1% ceramide VI. The data on the testosterone diffusion were affected by the exposure of the membrane to a water/ethanol solution over a prolonged period of time, indicating that such an organic solvent was able to modify the supermolecular organization of keratin and CERs.The keratin/CER membranes can represent a simplified model to assay the in vitro skin permeability study of small molecules

Train-the-trainer booklet bioeconomy and the UrBioFuture experience

Objective of this training is to bring your attention, as educators, to the importance of the bioindustry and the opportunities that it creates for the young people. In this booklet we will share with you tailored made educational and multimedia materials so you can use it in your classes and become the Ambassadors of UrBioFuture Experience

Graphene oxide doped polysulfone membrane adsorbers for the removal of organic contaminants from water

This work explored polysulfone (PS) – graphene oxide (GO) based porous membranes (PS-GO) as adsorber of seven selected organic contaminants of emerging concern (EOCs) including pharmaceuticals, personal care products, a dye and a surfactant from water. PS-GO was prepared by phase inversion method starting from a PS and GO mixture (5% w/w of GO). The porous PS-GO membranes showed asymmetric and highly porous micrometer sized pores on membrane top (diameter ≈20 μm) and bottom (diameter ≈2–5 μm) surfaces and tens of microns length finger like pores in the section. Nanomechanical mapping reveals patches of a stiffer material with Young modules comprised in the range 15–25 GPa, not present in PS pure membranes that are compatible with the presence of GO flakes on the membrane surfaces. PS-GO was immersed in EOCs spiked tap water and the adsorbance efficiency at different contact times and pH evaluated by HPLC analysis. Ofloxacin (OFLOX), benzophenone-3 (BP-3), rhodamine b (Rh), diclofenac (DCF) and triton X-100 (TRX) were removed with efficiency higher than 90% after 4 h treatments. Regeneration of PS-GO and reuse possibilities were demonstrated by washing with ethanol. The adsorption efficiencies toward OFLOX, Rh, DCF and carbamazepine (CBZ) were significantly higher than those of pure PS membrane. Moreover, PS-GO outperformed a commercial granular activated carbon (GAC) at low contact times and compared well at longer contact time for OFLOX, Rh, BP-3 and TRX suggesting the suitability of the newly introduced material for drinking water treatment

Eco-friendly electrospun membranes made of biodegradable polymers for wastewater treatment

The rapid population growth, associated with a rapid worldwide industrialization, is leading to an uncontrollable increase in environmental pollution of air and water. The World Water Council estimates that by 2030, 3.9 billion people will live in regions characterized as “water scarce,” and water scarcity is gradually becoming a big threat to food security, human health, and natural ecosystem

Outstanding traits and thermal behaviour for the identification of speciality animal fibres

The extra-fine, soft and warm fibres used by the textile industry for manufacturing high-quality, luxury textiles are obtained from the undercoat hair of several domestic mammals of the genera Capra, Bos, Camelus, and Lama. The demand for 'speciality fibres' by the fashion world represents an important opportunity for livelihoods, on condition that conservation of the wild species is preserved. Large scale trade of hair from wild goats hunted for meat or trophy and hybridisation of wild (Capra ibex) and domestic (Capra hircus) goats or wild Vicuna (Lama vicugna) and domestic Alpaca (Lama pacos), with the aim of improving fibre fineness and yield, would involve a risk of genetic pollution and would severely threaten conservation and biodiversity. This work describes fibre morphology and cell structure of fine fibres from the most important wild and domestic fibre producing species with the aim of enhancing traits for identification purposes. Microscopy investigation shows that exposure to thermal and nutritional stresses in the wild, lead to finer hair associated with lower rate of growth, yielding orientation and elongation of the cuticle cells. Differential scanning calorimetry reveals specie-specific differences in the internal structure of the fibre cortex, probably related to the process of hair keratinisation

Characterisation of keratin biomass from butchery and wool industry wastes

The chemical and structural characteristics of wool and horn-hoof were compared with the aim of better addressing possible exploitation of protein biomasses available as waste from textile industry and butchery. Amino acid analysis showed that wool has a higher amount of cystine and a lower amount of the amino acids that favour alpha-helix formation than horn-hoof. The difference in the alpha-helix content is confirmed by FTIR spectroscopy. Electrophoresis separation patterns showed two characteristic protein fractions related to low-sulphur proteins (between 60,000 and 45,000 Da) in wool, while different low-sulphur proteins are present in horn-hoof These data are partially confirmed by DSC analyses that showed different endothermic peaks at temperatures higher than 200 degrees C in the horn-hoof thermograms, probably due to denaturation of alpha-keratins at different molecular weights. Moreover. wool keratin was more hygroscopic and showed a higher extractability with reducing agents than horn-hoof On the basis of these results. waste wool is a more Suitable source than horn-hoof for uses involving protein extraction, but application can be envisaged also in surfactant foams for fire extinguishers and slow-release nitrogen fertilizer