Novel polysaccharide hybrid scaffold loaded with hydroxyapatite: Fabrication, bioactivity, and in vivo study

© 2018 Elsevier B.V. The main goal of this study was to produce a novel porous scaffold for rapid in vivo bone healing behavior. Lyophilization technique was used to produce this highly porous hybrid scaffold from Na-alginate (S) and hydroxyethylcellulose (HEC) impregnated with different concentration of hydroxyapatite (HA). After cross-linking the scaffolds, their incubation was carried out in simulated body fluid (SBF) for 4 weeks at 37 °C to investigate their bioactivity. A number of techniques were employed (e.g., XRD, FTIR, SEM, EDX, and texture analyzer) to characterize the designed scaffolds. It was observed that the mechanical properties of the scaffolds increase deformation energy (182 ± 16 J/m3) and rigidity gradient (19.44 ± 0.85 Pa) after loading with HA. Furthermore, the scaffolds were implanted in femur critical size defects (2 mm) of adult male Wistar rats for 6 weeks. In vitro and in vivo analyses demonstrated impressive bioactivity and biocompatibility for the prepared scaffolds, especially those containing HA. Based on the obtained results we conclude that the designed scaffolds are promising solutions for bone regeneration applications

Pharmaceutical particulates and membranes for the delivery of drugs and bioactive molecules [Editorial]

The delivery of drugs and bioactive molecules using pharmaceutical particulates and membranes are of great significance for various applications such as the treatment of secondary infections, cancer treatment, skin regeneration, orthopedic applications and others [...]

Novel zinc-silver nanocages for drug delivery and wound healing: Preparation, characterization and antimicrobial activities

Metal organic framework (MOF)-nanocages (MOF-NCs) in the form of zinc-based nanoparticles (NPs) were synthesized as drug carriers for the purpose of wound healing. The prepared NCs (single and bi-metallic with silver-MOF) were based on zinc and they were loaded with ascorbic acid (vitamin C) as a model drug which accelerates wound healing. The NCs were then investigated by several characterization techniques such as XRD, TEM, FTIR and BET surface area. Furthermore, the release behavior of the loaded ascorbic acid from the developed NCs was measured in phosphate buffer solution (PBS). NCs antibacterial activity was tested against strain of gram-positive bacteria (Staphylococcus aureus ATCC- 29213, Streptococcus pyogenes ATCC-19615 and Bacillus subtilis ATCC-6633), gram-negative bacteria strain (Pseudomonas aeruginosaATCC-27853and Escherichia coli ATCC-25922) and fungi (Candida albicans ATCC-10231).The physicochemical features of the NCs were confirmed by the results obtained from XRD and FTIR measurements. The particle size of the NCs was confirmed to be in the range of 30–50 nm. Prolonged drug release that was combined with impressive antibacterial activities, and good wound healing rates were also recognized for the zinc based NCs in comparison to commonly used Ag NPs. It is concluded that the current NCs are potentially suitable for wound healing and drug delivery applications

Influence of Niobium Pentoxide particulates on the properties of Brushite/Gelatin/Alginate membranes

Novel non-porous membranes were prepared by impregnating of nano-brushite and niobium pentoxide (Nb2O5) into a gelatin/alginate matrix. The physicochemical properties, morphology and mechanical properties of the prepared membranes were characterized using XRD, FTIR, SEM, TEM and universal testing machine, respectively. Swelling ability of the prepared membranes was determined in distilled water. The surfaces of the membranes were characterized by means of FTIR and SEM coupled with EDX after submersion in simulated body fluid (SBF) up to 15 days. Moreover, the calcium and phosphorus ion concentrations in the SBF were measured by UV-spectrophotometer. The in vitro drug release and the release mechanism of a model antibiotic, namely, ciprofloxacin (CFX), were tested in phosphate buffer saline (PBS) for 15 days. The antibacterial activities of the CFX-loaded membranes were tested against known microorganisms. The physicochemical properties, morphology, mechanical properties and swelling ability of the prepared membranes were found to be dependent on the presence of Nb2O5 allowing control of their properties. For example, the Nb2O5-loaded membranes exhibited a higher in vitro bioactivity and slower drug release compared to those of Nb2O5-free membranes. The CFX-loaded membranes also exhibited an excellent inhibition zones against the selected microorganisms. Overall, the prepared membranes have been found to be very promising for use in bone substitute’s applications

Multifunctional magnetite nanoparticles for drug delivery: preparation, characterisation, antibacterial properties and drug release kinetics

Multifunctional nanoparticles (NPs) with magnetic (M) and antibacterial properties were prepared for drug delivery purposes by a method involving co-precipitation synthesis. Partial and complete substitutions of ferrous ions (Fe2+) by copper ions (Cu2+) were carried out for the preparation of the magnetite NPs, which are designated as Cu0.5M and CuM, respectively, in this work. In addition, chitosan and ciprofloxacin were hybridized with the NPs from the previous step to achieve multifunctional properties. XRD, TEM, SEM/EDAX, VSM and FTIR were subsequently employed to characterize various properties of the prepared NPs, namely, crystallinity, nanostructure (size), particle morphology, elemental mapping, magnetic strength and chemical composition. Antibacterial properties of the NPs were tested against Bacillus cereus (Gram-positive bacteria), Escherichia coli (Gram-negative bacteria) and Candida albicans (yeast). Efficiency of the ciprofloxacin release was also studied for the drug-loaded NPs. It is demonstrated that the obtained NPs possess mixed phases with crystalline structures that are affected by the degree of Cu ion substitution (5-10nm (M), 2.5-3.5nm (Cu0.5M) and 11-16nm (CuM)). Saturation magnetization values of the NPs were recorded as 38.7, 3.5 and 1.3 emu/g, respectively. It was also found that the introduction of Cu ions in the NP samples improved the significance of their antibacterial activity, especially against Escherichia coli. Chitosan and ciprofloxacin were found to have stronger effects against Bacillus cereus and Escherichia coli and lesser effects against Candida albicans. However, the samples containing chitosan, ciprofloxacin and the higher Cu ion concentration exhibited strong influence against Candida albicans. During a study period of 30- days, the amounts of released drug from the tested NPs were 85, 26 and 20% of the originally loaded amount, respectively. Owing to the findings in this paper, the developed NPs are considered to have good potential for drug delivery applications and to study them further such as in pre-clinical studies

Anti-obesity drug delivery systems: recent progress and challenges

Obesity has reached an epidemic proportion in the last thirty years, and it is recognized as a major health issue in modern society now with the possibility of serious social and economic consequences. By the year 2030, nearly 60% of the global population may be obese or overweight, which emphasizes a need for novel obesity treatments. Various traditional approaches, such as pharmacotherapy and bariatric surgery, have been utilized in clinical settings to treat obesity. However, these methods frequently show the possibility of side effects while remaining ineffective. There is, therefore, an urgent need for alternative obesity treatments with improved efficacy and specificity. Polymeric materials and chemical strategies are employed in emerging drug delivery systems (DDSs) to enhance therapy effectiveness and specificity by stabilizing and controlling the release of active molecules such as natural ingredients. Designing DDSs is currently a top priority research objective with an eye towards creating obesity treatment approaches. In reality, the most recent trends in the literature demonstrate that there are not enough in-depth reviews that emphasize the current knowledge based on the creation and design of DDSs for obesity treatment. It is also observed in the existing literature that a complex interplay of different physical and chemical parameters must be considered carefully to determine the effectiveness of the DDSs, including microneedles, for obesity treatment. Additionally, it is observed that these properties depend on how the DDS is synthesized. Although many studies are at the animal-study stage, the use of more advanced DDS techniques would significantly enhance the development of safe and efficient treatment approaches for obese people in the future. Considering these, this review provides an overview of the current anti-obesity treatment approaches as well as the conventional anti-obesity therapeutics. The article aims to conduct an in-depth discussion on the current trends in obesity treatment approaches. Filling in this knowledge gap will lead to a greater understanding of the safest ways to manage obesity.</p

Egyptian corals-based calcium silicate (CaS) nanopowders doped with zinc/copper for improved chemical stability and treatment of calvarial defects

Developing low-cost nano-biomaterials using locally available raw materials is gaining significant prominence recently, e.g., to meet the UN’s sustainable development goals (Goal 3). In this work, amorphous calcium silicate (CaS) nanopowders were prepared from Egyptian corals (CaCO3) as a low-cost bone restoration material due to their excellent bonding abilities with surrounding bone tissues, which in turn accelerated the bone healing process. Some of the developed CaS nanopowders was doped with different concentrations of Cu2+ and Zn2+ at the expense of the inherent Ca2+ in the raw materials. The nanopowders were characterized using X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), scanning electron microscope with energy-dispersive X-ray spectrometry (SEM-EDX), transmission electron microscope (TEM) and Brunauer-Emmett-Teller (BET) surface area measurements. Mechanical and bactericidal properties of the nanopowders were assessed followed by well-defined examinations of their abilities to support cell viability, proliferation and differentiation against osteosarcoma cells (MG63 cell lines). The obtained nanopowders were confirmed to be amorphous in nature with particle diameters mostly in two size ranges, namely, 5–10 nm and 15–92 nm. The nanopowders were found to have a good surface area influenced by the type of dopant materials. Notable enhancement in the mechanical (up to 6.76 MPa compressive strength) and antibacterial behaviors of the CaS nanopowders were observed after Zn2+ doping. The number of the differentiated cells after 72 h of incubation was increased, especially for CaS silicate Zn2+ doped nanopowders. Following these examinations of the nanopowders, their utility for the treatment of calvarial (top part of the skull) defects in a rat model was investigated. The developed Cu2+ or Zn2+ doped nanopowders enhanced the healing rate of calvarial defects and they demonstrated impressive biosafety towards repairing vital organs (brain, liver and kidney).</p

Biocompatibility of hydroxyethyl cellulose/glycine/RuO₂ composite scaffolds for neural-like cells

Fabrication of scaffolds for nerve regeneration is one of the most challenging topics in regenerative medicine at the moment, which is also interlinked with the development of biocompatible substrates for cells growth. This work is targeted towards the development of green biomaterial composite scaffolds for nerve cell culture applications. Hybrid scaffolds of hydroxyethyl cellulose/glycine (HEC/Gly) composite doped with different concentrations of green ruthenium oxide (RuO2) were synthesized and characterized via a combination of different techniques. X-rays diffraction (XRD) and differential scanning calorimetry (DSC) analyses showed a crystalline nature for all the samples with noticeable decrease in the peak intensity of the fabricated scaffolds as compared to that for pure glycine. Fourier transform infrared spectroscopy (FTIR) tests revealed an increase in the vibrational bands of the synthesized RuO2 containing scaffolds which are related to the functional groups of the natural plant extract (Aspalathuslinearis) used for RuO2 nanoparticles (NPs) synthesis. Scanning electron microscopy (SEM) results revealed a 3D porous structure of the scaffolds with variant features attributed to the concentration of RuO2 NPs in the scaffold. The compressive test results recorded an enhancement in mechanical properties of the fabricated scaffolds (up to 8.55MPa), proportionally correlated to increasing the RuO2 NPs concentration in HEC/Gly composite scaffold. Our biocompatibility tests revealed that the composite scaffolds doped with 1 and 2ml of RuO2 demonstrated the highest proliferation percentages (152.2 and 135.6%) compared to control. Finally, the SEM analyses confirmed the impressive cells attachments and differentiation onto the scaffold surfaces as evidenced by the presence of many neuron-like cells with apparent cell bodies and possessing few short neurite-like processes. The presence of RuO2 and glycine was due to their extraordinary biocompatibility due to their cytoprotective and regenerative effects. Therefore, we conclude that these scaffolds are promising for accommodation and growth of neural-like cells.</p

Magnetic nanosystems substituted with zinc for enhanced antibacterial, drug delivery and cell viability behaviours

Nanoparticles (NPs) of magnetite (M) and zinc ferrites (Zn0.5M and ZnM) with different zinc concentrations were synthesized through a co-precipitation method and coated with chitosan containing ciprofloxacin antibiotic to enhance the cells compatibility to these nanosystems. The prepared magnetic nanoparticles (MNPs), chitosan/MNPs and ciprofloxacin/chitosan/MNPs were characterized using X-ray diffraction (XRD), transmittance electron microscopy (TEM), scanning electron microscopy (SEM) accessorized with energy dispersive X-rays (EDAX), vibrating-sample magnetometer (VSM), Fourier transform infrared (FTIR) and BET surface area measurements. Antibacterial properties of the MNPs were examined against Candida albicans (yeast), Bacillus cereus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria).The drug-loaded NPs were also studied for their efficiency of ciprofloxacin release. The average crystallite size of the fabricated NPs was 10.4 nm (Fe3O4) and 14 nm (ZnFe2O4) for samples M and Zn0.5M, respectively. The surface areas of the achieved specimens were recorded to be 145.92±2.32, 102.94±0.39 and 168.71±2.05 m²/g for M, Zn0.5M and ZnM, respectively. The saturation magnetization values were determined to be approximately 38.7, 60.6 and 2 emu/g for M, Zn0.5M and ZnM, respectively. It was revealed that the bactericidal activity towards the tested strains was highly pronounced for the nanosytems containing ciprofloxacin drug alongside with those substituted with zinc. During a period of 30 days, the total dosage of released ciprofloxacin from CipChM, CipChZnM and CipChZn0.5M was 82, 90 and 96%, respectively. Finally, cells viability and proliferation of different cell lines were found to be increased by the developed nanosystems, especially by those containing zinc and chitosan in the presence of extra MNPs. </p

Nanoparticle- and nanoporous-membrane-mediated delivery of therapeutics

Pharmaceutical particulates and membranes possess promising prospects for delivering drugs and bioactive molecules with the potential to improve drug delivery strategies like sustained and controlled release. For example, inorganic-based nanoparticles such as silica-, titanium-, zirconia-, calcium-, and carbon-based nanomaterials with dimensions smaller than 100 nm have been extensively developed for biomedical applications. Furthermore, inorganic nanoparticles possess magnetic, optical, and electrical properties, which make them suitable for various therapeutic applications including targeting, diagnosis, and drug delivery. Their properties may also be tuned by controlling different parameters, e.g., particle size, shape, surface functionalization, and interactions among them. In a similar fashion, membranes have several functions which are useful in sensing, sorting, imaging, separating, and releasing bioactive or drug molecules. Engineered membranes have been developed for their usage in controlled drug delivery devices. The latest advancement in the technology is therefore made possible to regulate the physico-chemical properties of the membrane pores, which enables the control of drug delivery. The current review aims to highlight the role of both pharmaceutical particulates and membranes over the last fifteen years based on their preparation method, size, shape, surface functionalization, and drug delivery potential