A sunscreen nanoparticles polymer based on prolonged period of protection

UV rays are one of the most dangerous factors that harm the skin. There is continuous improvement in getting an effective sunscreen that protects the skin from excessive exposure to UV rays. Typically, phenylbenzimidazole-5-sulfonic acid (PBSA) is used as a sun blocking agent, but its disadvantage is that it can photodegrade and cause cell damage. In our work, PBSA was encapsulated in niosomes nanoparticles then coated with chitosan-aloe vera (CS-nio-aloe/PBSA) to form a carrier polymer with novel and potent properties. This polymer controls PBSA release and epidermal penetration. Characterization of CS-nio-aloe/PBSA polymer nanoparticles through transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS). The carrier polymer release rate was studied in vitro and epidermal permeability to coated PBSA was assessed using mouse skin. The nanoparticle polymer containing sunscreen was effectively prepared with an encapsulation efficiency of 80%. The formulation (CS-nio-aloe/PBSA) was completely deposited on the surface of the skin. This supports its use to protect the skin, and its nanostructures stimulate the release of PBSA for a longer period. Encapsulation of PBSA in CS-nio-aloe nanoparticles could allow for further cellular preservation, UV protection, control of free PBSA, and limited penetration through the mouse skin epidermis.

A study of the electrophoretic deposition of polycaprolactone-chitosan-bioglass nanocomposite coating on stainless steel (316L) substrates

In this research, bioglass nanoparticles were synthesized via sol-gel method and a polycaprolactone-chitosan-bioglass nanocomposite coating was formed on SS316L substrate using electrophoretic deposition method. Then, the effects of voltage and deposition time on morphology, thickness, roughness, and wettability of final coating were investigated. Finally, biocompatibility and toxicity of the coating were evaluated. The results showed that increase of both time and voltage enhanced the thickness, roughness, and wettability of coating. Also, increase of deposition time increased the agglomeration. Therefore, it can be concluded that voltage of 20 V and time of 10 min are suitable for the formation of a uniform agglomerate-free coating. The presence of bioglass nanoparticles also led to the increase of roughness and improvement of polycaprolactone hydrophobicity. The results also showed higher bioactivity in polycaprolactone-chitosan-1% bioglass nanocomposite coating sample. This sample had a roughness ( Ra) of 1.048 ± 0.037 μm and thickness of 2.54 ± 0.14 μm. In summary, the results indicated that coating of polycaprolactone-chitosan-bioglass nanocomposite on SS316L substrate could be a suitable surface treatment to increase its in vivo bioactivity and biocompatibility.

Accelerating skin barrier repair using novel bioactive magnesium-doped nanofibers of non-mulberry silk fibroin during wound healing

Novel magnesium doped non-mulberry silk fibroin nanofibers with ability to enhance skin barrier function were successfully fabricated using electrospinning technique for wound healing applications. Magnesium nanoparticles incorporated in the electrospun nanofibers releases Mg2+ ions at the site of implementation. The effect of Mg2+ is of considerable concern in wound healing due to its skin barrier repair ability and its role in blood coagulation. The physicochemical characterization of the scaffold was investigated by determining the morphology and secondary structure confirmation. The effects of Mg2+ ions in silk fibroin microenvironment have been evaluated using SEM, XRD, and FTIR to confirm the incorporation of magnesium in the film. The aim of this study is to see the effect of doped Mg on the structural, physical, and biological properties of non-mulberry silk fibroin (NSF) film. The magnesium doped nanofibrous film exhibited enhanced mechanical property, satisfactory blood clotting ability, and good in vitro degradability. This silk fibroin-based film mimicking extracellular matrix for skin regeneration were constructed using electrospinning technique. The wound healing efficiency of prepared nanofibers were evaluated in full-thickness wound models of rat. The Mg doped silk fibroin film exhibited faster wound healing activity (14 days) among all experimental group. The study indicates the potential of magnesium-doped silk /PVA film as skin substitute film.

Cell proliferative properties of Forcespinning® nopal composite nanofibers

In this study, Forcespinning® was used to produce nanofibers composed of Opuntia cochenillifera, “nopal,” mucilage (N) extract, chitosan (CH), and pullulan (PL) (N/CH/PL). These nopal-incorporating nanofibers were examined for their ability to sustain adhesion and proliferation of mouse embryonic fibroblast (NIH 3T3) cells. After a 6-day incubation period, N/CH/PL nanofibers displayed robust cell proliferation, with continued cell growth after an extended incubation period of 14 days. These results demonstrate that natural bioactive compounds can be combined with biodegradable polymers to provide an enhanced environment for cell growth, suggesting potential natural active ingredients as alternatives in wound dressings.

Preparation of liposomal nanocarrier by extruder to enhance tumor accumulation of paclitaxel

Despite the wide-spectrum and effective anti-cancer activity of paclitaxel (PTX), their low solubility and side effects are the main challenges in their clinical application. In this study, a model paclitaxel-encapsulated nanoliposome (NLips-PTX) carrier was synthesized to enhance PTX solubility and increase its passive accumulation at the tumor site. Soy lecithin and cholesterol at a 9:1 ratio were used to prepare the nano-sized liposomes through the thin-film hydration followed by extrusion technique. The prepared spherical NLips-PTX liposomes with an average size of about 150 nm and high uniformity were characterized by DLS and TEM. PTX load efficiency of NLips was determined at about 85% by HPLC. NLips-PTX also showed a therapeutic effect toward breast cancer cells (MCF-7) in a dose- and time-dependent manner via in vitro cellular uptake and a cytotoxicity study. This research indicates that extrusion is a simple and convenient method for nano-sizing and homogenising liposome suspension for potentially effective delivery of drug to target tumor sites.

Synthesis and characterization of levan hydrogels and their use for resveratrol release

Considering the need for systematic studies on levan based hydrogels to widen their use in drug delivery systems and biomedical applications, this study is mainly focused on the synthesis and comprehensive characterization as well as drug release properties of hydrogels based on Halomonas levan (HL) and its chemical derivatives. For this, hydrolyzed and phosphonated HL derivatives were chemically synthesized and then cross-linked with 1,4-Butanediol diglycidyl ether (BDDE) and the obtained hydrogels were characterized in terms of their swelling, adhesivity, and rheological properties. Both native and phosphonated HL hydrogels retained their rigid gel like structure with increasing shear stress levels and tack test analysis showed superior adhesive properties of the phosphonated HL hydrogels. Moreover, hydrogels were loaded with resveratrol and entrapment and release studies as well as cell culture studies with human keratinocytes were performed. Biocompatible and adhesive features of the hydrogels confirmed their suitability for tissue engineering and drug delivery applications.

Development of poly(ethyleneimine) grafted amphiphilic copolymers: Evaluation of their cytotoxicity and ability to complex DNA

Poly(ethyleneimine) (PEI) is one of the most widely used cationic polymers for gene delivery. The high molecular weight polymer, which is commercially available, is highly efficient but also very cytotoxic. The reduction in charge density by using nonlinear architectures based on low molecular weight (LMW) PEI is a promising approach to produce safer DNA-vectors. Herein, a group of cationic graft copolymers with different composition containing a hydrophobic biocompatible backbone and LMW linear PEI (lPEI) grafts obtained by ring opening polymerization and click chemistry was studied. The self-assembly and DNA complexation behavior of these materials was analyzed by the gel retardation assay, zeta potential measurements, and dynamic light scattering. The copolymers formed positively charged particles in water with average sizes between 270 and 377 nm. After they were added to DNA in serum-free medium, these particles acquired negative/near-neutral charges and increased in size depending on the N/P ratio. All copolymers showed reduced cytotoxicity compared to the 25 kDa lPEI used as reference, but the transfection efficiency was reduced. This result suggested that the cationic segments were too small to fully condense the DNA and promote cellular uptake, even with the use of several grafts and the introduction of hydrophobic domains. The trends found in this research showed that a higher degree of hydrophobicity and a higher grafting density can enhance the interaction between the copolymers and DNA. These trends could direct further structural modifications in the search for effective and safe vectors based on this polycation.

Wound healing and antibacterial activities of water-soluble chitosan nanoparticles and excretion/secretion as a natural combination from medicinal maggots, Lucilia cuprina

Wounds management takes a high interest in the medical field and the addition of antimicrobial agents in an assortment of wound dressings leads to delay the wound healing. This study aimed at preparing natural combination between excretion/secretion (ES) and water-soluble chitosan nanoparticles (from Lucilia cuprina maggots) and investigating its antibacterial and wound healing activities. ES of maggots was collected, and the water-soluble chitosan nanoparticles (WSCNPs) were prepared and characterized. Antibacterial activities of combinations were evaluated against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Proteus vulgaris. ES-WSC-2 combination that contains 50% ES and 1% WSCNPs showed highest antibacterial activity against all tested bacteria compared to the other combinations. In vitro, the ES-WSC-2 combination was used to study the wound healing activity by scratch assay. The synergism between ES and WSCNPs (in ES-WSC-2 combination) accelerated the wound healing rate which suggests the use of this combination as an effective natural antibacterial and wound healing agent.

Enhanced anticancer efficacy of docetaxel through galbanic acid encapsulated into PLA-PEG nanoparticles in treatment of colon cancer, in vitro and in vivo study

Cancer is one of the most leading causes of human mortality and despite outstanding breakthrough in introducing new therapeutic approaches, the clinical outcomes are disappointing. Therefore, extensive research in design and preparation of more efficient drug delivery systems can open a window to shine light into the therapeutic modality. In this study, we evaluated the effect of galbanic acid (GBA) encapsulated into PLA-PEG nanoparticles (NPs) to enhanced anticancer efficacy of docetaxel (DOC) for the treatment of colon cancer. Prepared NPs were characterized by different methods in terms of size, zeta potential, and drug loading capacity. MTT assay was used to investigate the anti-proliferation of GBA-loaded PEG-PLA NPs along with DOC. The therapeutic efficacy of PEG-PLA@GBA NPs & DOC was further investigated in C26 tumor-bearing BALB/c mice model. The resulting NPs were narrowly distributed (PDI = 0.06) with the mean diameter of 148 ± 9 nm with somewhat negative charge. GBA were efficiently loaded into mPEG-PLA NPs with encapsulation efficiency of about 40% ± 3. Cytotoxicity studies showed that NPs loaded with GBA and fixed concentration of docetaxel (20 nM) have higher toxicity (IC50 = 6 ± 1.8 µM) than either PEG-PLA@GBA (IC50 = 8 ± 1.2 µM) or free GBA (IC50 = 15 ± 3.5 µM) in C26 cells. In vivo studies revealed a synergistic effect of PEG-PLA@GBA NPs and DOC on tumor growth inhibition and survival rate in comparison with monotherapy approach.

Biofabrication of controllable alginate hydrogel cell scaffolds based on bipolar electrochemistry

Bipolar electrochemistry successfully realized the electrodeposition of calcium alginate hydrogels in specific target areas in tissue engineering. However, the shape and quantity of three-dimensional cannot be accurately controlled. We presented a novel growth model for fabricating hydrogels based on bipolar electrochemical by patterned bipolar electrodes using photolithography. This work highlights pattern customization and quantitative control of hydrogels in cell culture platforms. Furthermore, alginate hydrogels with different heights can be controlled by adjusting the key parameters of the growth model. This strategy exhibits promising potential for cell-oriented scaffolds in tissue engineering.