A biotechnological approach for the production of new protein bioplastics.

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.

Microfluidic manufacturing of tioconazole loaded keratin nanocarriers: Development and optimization by design of experiments.

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.

Novel Nanostructured Scaffolds of Poly(butylene trans-1,4-cyclohexanedicarboxylate)-Based Copolymers with Tailored Hydrophilicity and Stiffness: Implication for Tissue Engineering Modeling.

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.

The ad hoc chemical design of random PBS-based copolymers influences the activation of cardiac differentiation while altering the HYPPO pathway target genes in hiPSCs.

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.

Synthesis and Properties of Sucrose- and Lactose-Based Aromatic Ester Surfactants as Potential Drugs Permeability Enhancers.

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.

Microfluidics assembly of inhalable liposomal ciprofloxacin characterised by an innovative in vitro pulmonary model.

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.

3D-printed EVA-based patches manufactured by direct powder extrusion for personalized transdermal therapies.

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.

A microfluidic approach to fabricate sucrose decorated liposomes with increased uptake in breast cancer cells.

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.

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.

Eco-Sustainable Silk Fibroin/Pomegranate Peel Extract Film as an Innovative Green Material for Skin Repair.

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.

Keratin/Polylactic acid/graphene oxide composite nanofibers for drug delivery.

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.

Bioactive Keratin and Fibroin Nanoparticles: An Overview of Their Preparation Strategies.

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.

Cyanine-Doped Nanofiber Mats for Laser Tissue Bonding.

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.

High-Resolution Ultrasound Spectroscopy for the Determination of Phospholipid Transitions in Liposomal Dispersions.

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.

Silk Fibroin and Pomegranate By-Products to Develop Sustainable Active Pad for Food Packaging Applications.

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.

Effects of the Blending Ratio on the Design of Keratin/Poly(butylene succinate) Nanofibers for Drug Delivery Applications.

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.

Optically activated and interrogated plasmonic hydrogels for applications in wound healing.

We disclose the use of hybrid materials featuring Au/Ag core/shell nanorods in porous chitosan/polyvinyl alcohol scaffolds for applications in tissue engineering and wound healing. The combination of Au and Ag in a single construct provides synergistic opportunities for optical activation of functions as near infrared laser tissue bonding, and remote interrogation to return parameters of prognostic relevance in wound healing monitoring. In particular, the bimetallic component ensures optical tunability, enhanced shelf life and photothermal stability, serves as a reservoir of germicidal silver cations, and changes in near-infrared and visible color according to the environmental level of oxidative stress. At the same time, the polymeric blend is ideal to bind connective tissue upon photothermal activation, and to support fabrication processes that provide high porosity, such as electrospinning, thus putting all the premises for cellular repopulation and antimicrobial protection.

Effect of Chemically Engineered Au/Ag Nanorods on the Optical and Mechanical Properties of Keratin Based Films.

In this work we report the preparation and characterization of free-standing keratin-based films containing Au/Ag nanorods. The effect of nanorods surface chemistry on the optical and mechanical properties of keratin composite films is fully investigated. Colloid nanorods confer to the keratin films interesting color effects due to plasmonic absorptions of the metal nanostructures. The presence of metal NRs induces also substantial change in the protein fluorescence emission. In particular, the relative contribution of the ordered-protein aggregates emission is enhanced by the presence of cysteine and thus strictly related to the surface chemistry of nanorods. The presence of more packed supramolecular structures in the films containing metal nanorods (in particular cysteine modified ones) is confirmed by ATR measurements. In addition, the films containing nanorods show a higher Young's modulus compared to keratin alone and again the effect is more pronounced for cysteine modified nanorods. Collectively, the reported results indicate the optical and mechanical properties of keratin composites films are related to a common property and can be tuned simultaneously, paving the way to the optimization and improvement of their performances and enhancing the exploitation of keratin composites in highly technological optoelectronic applications.

Keratin/Hydrotalcites Hybrid Sponges as Promising Adsorbents for Cationic and Anionic Dyes.

In this work, keratin sponges were prepared by freeze-drying method and tested for adsorption of Azure A and Methyl Orange dyes. The obtained materials showed a porosity of 99.92% and a mean pore size dimension of about 91 µm. The use of oxidized sucrose with a heating treatment at 150°C was demonstrated to be a useful crosslinking procedure alternative to the conventional glutaraldehyde. Keratin sponges showed a maximum adsorption capacity of 0.063 and of 0.037 mmol/g for Azure A and Methyl Orange, respectively. The absorption of the cationic dye Azure A onto keratin sponges was better described by Freundlich model while the isotherm adsorption of the anionic Methyl Orange was found to correlate with both Langmuir and Freundlich models. The mean free energies evaluated by using the D-R model indicated a physisorption of Methyl Orange and a chemisorptions of Azure A onto keratin sponges. Finally, the functionalization of keratin sponges with Zn Al hydrotalcites nanoparticles did not affect the adsorption performances of the adsorbent toward the cationic dye Azure A, while it improved those toward the anionic Methyl Orange, increasing the related removal efficiencies from 43 to 96%. Collectively, the reported data indicates that the combination of keratin with hydrotalcites nanoparticles is a good strategy to obtain more functional adsorbent materials of potential interest for water treatment and purification.

Polydopamine Nanoparticle-Coated Polysulfone Porous Granules as Adsorbents for Water Remediation.

Water purification technologies possibly based on eco-sustainable, low cost, and multifunctional materials are being intensively pursued to resolve the current water scarcity and pollution. In this scenario, polysulfone hollow porous granules (PS-HPGs) prepared from scraps of the industrial production of polysulfone hollow fiber membranes were recently introduced as adsorbents and filtration materials for water and air treatment. Here, we report the functionalization of PS-HPGs with polydopamine (PD) nanoparticles for the preparation of a new versatile and efficient adsorbent material, namely, PSPD-HPGs. The in situ growth of PD under mild alkaline oxidative polymerization allowed us to stably graft PD on polysulfone granules. Enhanced removal efficiency of ofloxacin, an antibiotic drug, with an improvement up to 70% with respect to the pristine PS-HPGs, and removal of Zn(II) and Ni(II) were also observed after PD modification. Remarkably, removal of Cu(II) ions with an efficiency up to 80% was observed for PSPD-HPGs, whereas no adsorption was found for the PD-free precursor. Collectively, these data show that modification with a biocompatible polymer such as PD provides a simple and valuable tool to enlarge the field of application of polysulfone hollow granules for water remediation from both organic and metal cation contaminants.