In vitro sustained release study of gallic acid coated with magnetite-PEG and magnetite-PVA for drug delivery system

Zinc/aluminum-layered double hydroxide-gallic acid doped carboxymethyl cellulose nanocomposite films for wound healing

Effective loading and delivering the wound healing-based materials to the wound site and area with an optimum concentration and limited cytotoxicity are essential for a complete and fast healing process. Here, we have designed Zn/Al-LDH nanoparticles-loaded CMC films for encapsulation and delivery of gallic acid (GA) in order to develop an effective and efficient wound-healing scaffold. The physicochemical properties of the prepared Zn/Al-LDH nanohybrids were thoroughly characterized by several characterization techniques, such as FESEM, Hi-TEM, FTIR, and XRD techniques. The thermal properties of the scaffolds were evaluated by DSC and TGA analysis. The release profiles of GA from fabricated films were studied over 8 h by UV-vis spectroscopy. In vitro drug release studies in PBS solutions with pH 7.4 showed a mono-phasic profile in which the liberation of the drug mainly occurred by scaffold erosion and increased by increasing the experiment period. The in vitro antibacterial activity of Zn/Al-LDH-GA-loaded CMC films was assessed by disk diffusion and cell viability contact tests. The results showed the desired antibacterial activity against Staphylococcus aureus and Escherichia coli bacteria. Incorporating GA within CMC and CMC-Zn/Al-LDH films rereleased good cytocompatibility at the studied incubation time and different concentrations toward human normal HFF cell line than the free drug. The results of the present study indicated that the Zn/Al-LDH and Zn/Al-LDH-GA-loaded CMC have promising wound healing features to further develop a better future for clinical remedy of the different non-healing and hard-to-heal wounds.

Significance of Capping Agents of Colloidal Nanoparticles from the Perspective of Drug and Gene Delivery, Bioimaging, and Biosensing: An Insight

The over-growth and coagulation of nanoparticles is prevented using capping agents by the production of stearic effect that plays a pivotal role in stabilizing the interface. This strategy of coating the nanoparticles’ surface with capping agents is an emerging trend in assembling multipurpose nanoparticles that is beneficial for improving their physicochemical and biological behavior. The enhancement of reactivity and negligible toxicity is the outcome. In this review article, an attempt has been made to introduce the significance of different capping agents in the preparation of nanoparticles. Most importantly, we have highlighted the recent progress, existing roadblocks, and upcoming opportunities of using surface modified nanoparticles in nanomedicine from the drug and gene delivery, bioimaging, and biosensing perspectives.

Novel Iron Oxide Nanoparticles Induce Ferroptosis in a Panel of Cancer Cell Lines

The use of nanomaterials rationally engineered to treat cancer is a burgeoning field that has reported great medical achievements. Iron-based polymeric nano-formulations with precisely tuned physicochemical properties are an expanding and versatile therapeutic strategy for tumor treatment. Recently, a peculiar type of regulated necrosis named ferroptosis has gained increased attention as a target for cancer therapy. Here, we show for the first time that novel iron oxide nanoparticles coated with gallic acid and polyacrylic acid (IONP–GA/PAA) possess intrinsic cytotoxic activity on various cancer cell lines. Indeed, IONP–GA/PAA treatment efficiently induces ferroptosis in glioblastoma, neuroblastoma, and fibrosarcoma cells. IONP–GA/PAA-induced ferroptosis was blocked by the canonical ferroptosis inhibitors, including deferoxamine and ciclopirox olamine (iron chelators), and ferrostatin-1, the lipophilic radical trap. These ferroptosis inhibitors also prevented the lipid hydroperoxide generation promoted by the nanoparticles. Altogether, we report on novel ferroptosis-inducing iron encapsulated nanoparticles with potent anti-cancer properties, which has promising potential for further in vivo validation.

Preparation and characterisation of gallic acid loaded carboxymethyl chitosan nanoparticles as drug delivery system for cancer treatment

Gallic acid (GA) is a natural phenolic compound with antioxidant, anti-proliferative, and anticancer effects. However, the potential of GA as an anticancer agent is restricted by its poor absorption, rapid elimination, and low bioavailability. Nanostructure-drug carriers have opened up a new field in cancer therapy by improving the efficacy of drugs. In this work, we developed a nanoformulation of GA in carboxymethyl chitosan (CMC). The particle size, surface charge and molecular structure of the CMC NPs loaded and unloaded with GA were measured using TEM, DLS and FTIR spectroscopy, respectively. The dielectric parameters (permittivity ε′ and dielectric loss ε″) were measured in the frequency range (0.1 Hz–5 MHz) at room temperature. Additionally, the in-vitro anti-cancer effects of the GA, CMC NPs, and GA-CMC NPs were tested against human colon carcinoma (HCT-116), human breast carcinoma (MCF-7), and normal skin fibroblast cells (BJ1) using MTT assay. TEM confirmed that the NPs have a spherical morphology within the size range of 15 nm. DLS studies revealed NPs with a mean diameter of 31.06 nm. The zeta potential results indicated the high suspension stability of the prepared nanoformulation. The FTIR results indicated the interaction between GA and CMC NPs. The dielectric study showed a decrease within the ε″ and conductivity values of GA-CMC NPs which confirmed the successful encapsulation of GA within the CMC NPs. Cytotoxicity studies indicated that the GA-CMC NPs showed specific toxicity towards cancer cells and non-toxicity to normal cells. Overall, these results indicate that the GA-CMC NPs will be an efficient nanocarrier for delivering gallic acid to cancer cells.

Design and Synthesis of Multipotent Antioxidants for Functionalization of Iron Oxide Nanoparticles

Multipotent antioxidants (MPAO) were synthesized and characterized by FTIR, NMR. The functionalized nanoparticles (IONP@AO) were characterized by FTIR, XRD, Raman, HRTEM, FESEM, VSM, and EDX. IONP@AO1 and IONP@AO2 have average particles size of 10 nm and 11 nm, respectively. The functionalized IONP@AO has a superparamagnetic nature, with saturation magnetization of 45 emu·g−1. Structure-based virtual screening of the designed MPAO was performed by PASS analysis and ADMET studies to discover and predict the molecule’s potential bioactivities and safety profile before the synthesis procedure. The half-maximal inhibitory concentration (IC50) of DPPH analysis results showed a four-fold decrease in radical scavenging by IONP@AO compared to IONP. In addition to antioxidant activity, IONP@AO showed suitable antimicrobial activities when tested on various bacterial and fungal strains. The advantage of the developed nanoantioxidants is that they have a strong affinity towards biomolecules such as enzymes, proteins, amino acids, and DNA. Thus, synthesized nanoantioxidants can be used to develop biomedicines that can act as antioxidant, antimicrobial, and anticancer agents.

Surface Functionalization of Magnetite Nanoparticles with Multipotent Antioxidant as Potential Magnetic Nanoantioxidants and Antimicrobial Agents

Functionalized magnetite nanoparticles (Fe₃O₄) were prepared using the coprecipitation method followed by functionalization with a multipotent antioxidant (MPAO). The MPAO was synthesized and analyzed using FTIR and NMR techniques. In this study, the functionalized nanoparticles (IONP@AO) were produced and evaluated using the FTIR, XRD, Raman, HRTEM, FESEM, VSM, and EDX techniques. The average determined particle size of IONP@AO was 10 nanometers. In addition, it demonstrated superparamagnetic properties. The magnitude of saturation magnetization value attained was 45 emu g⁻¹. Virtual screenings of the MPAO’s potential bioactivities and safety profile were performed using PASS analysis and ADMET studies before the synthesis step. For the DPPH test, IONP@AO was found to have a four-fold greater ability to scavenge free radicals than unfunctional IONP. The antimicrobial properties of IONP@AO were also demonstrated against a variety of bacteria and fungi. The interaction of developed nanoantioxiants with biomolecules makes it a broad-spectrum candidate in biomedicine and nanomedicine.

Antimicrobial and antioxidant therapy with bioactive plant molecules on Fe3O4 phytohybrid nanoplatforms

Background

Nanobiomedicines have gained increasing attention for their potential to improve efficacy and are emerging as a promising therapeutic paradigm. Magnetic nanoconjugates loaded with bioactive drugs have the advantage of sustained circulation in the bloodstream and significantly reduced toxicity of therapeutic agents in a precise manner. The well-developed surface chemistry of Fe3O4 has led to the development better tools, promoting them as nanoplatforms with potential technological applications in biomedical sciences.

Results

Fe3O4 phytohybrids with Laxmitaru extract as the primary coating and loaded with Eugenol and Ylang-Ylang essential oils were successfully synthesized. The X-ray diffraction technique has revealed the high purity nanoparticle materials, as no additional impurity peaks were observed. Fourier transform infra-red spectra have confirmed the presence of a primary coating of Laxmitaru extract and a secondary layer of essential oil, as additional peaks and broadening are observed in drug-loaded Fe3O4 nanoparticles. Magnetic susceptibility values indicate the material's superparamagnetic nature. Transmission electron microscopy images have ensured that the particles were spherical, monodispersed, and in the range of 4.30 nm to 13.98 nm. Antimicrobial studies show inhibition zones on the microorganisms S. Aureus and E. Coli with enhanced activity. Drug entrapment efficiency studies revealed the encapsulation of drug molecules onto Fe3O4-Laxmitaru composite. Dynamic light scattering studies confirm the increase in hydrodynamic size, indicating the loading of essential oils and the decrease in polydispersity index ensures monodispersed nanoparticles. The antioxidant study showed the essential oils retained their antioxidant activity even after they were conjugated on Fe3O4-Lax composites.

Conclusions

Laxmitaru phytochemical-coated Fe3O4 nanoparticles were successfully conjugated with Eugenol and Ylang-Ylang essential oils. Our results provide a model therapeutic approach for the development of new alternative strategies for enhancing antimicrobial and antioxidant therapy, with potential advantages in the field of nanobiomedicine.

Stabilization of Etoricoxib Nanosuspension Using Acacia chundra Gum and Copolymers: Preparation, Characterization, and In Vitro Cytotoxic Study

Present communication deals with the stabilization of etoricoxib nanosuspension using Acacia chundra gum and its acrylamide-grafted and carboxymethylated copolymers. Acrylamide grafting and carboxymethylation of A. chundra gum were carried out and synthesized copolymers were characterized. Ultrasound-assisted solvent-antisolvent method was utilized to co-precipitate the stabilizers over etoricoxib nanoprecipitates. A 3² full factorial design was used to evaluate the effect of independent variables, that is, the concentration of drug and stabilizer over the dependent variables, that is, particle size (PS), and entrapment efficiency (EE%) of nanoparticles. The effect of process parameters over super saturation, nucleation, and PS were studied and the role of mixing and ultrasound radiation was correlated. FTIR, DSC, and ¹H NMR analysis showed a significant difference between the copolymers. The application of stabilizers leads to the synthesis of small, spherical, no aggregated, and composite nanoparticles. PS growth analysis after 45 days showed no sign of "Ostwald repining" and aggregation. Optimized formulations prepared using A. chundra gum (formulation K9), acrylamide-grafted (formulation A8), and carboxymethylated (formulation C1) copolymers showed t₈₀% in 190, 270, and 170 min, respectively. Cytotoxic studies showed that the formulation A8 had better control over cell growth than the pure drug against MCF-7 cell line. The results indicated that the A. chundra gum and its acrylamide and carboxymethylated copolymers can be easily synthesized and utilized for the fabrication of stabilized nanosuspension.

Exploitation of new approach to control of environmental pathogenic bacteria causing bovine clinical mastitis using novel anti-biofilm nanocomposite

New approaches are required for prevention and control of biofilm-producing bacteria and consequently mitigating the health problems of bovine clinical mastitis. This work designed to determine prevalence rates of biofilm-producing bacteria that causing bovine clinical mastitis and evaluate the anti-biofilm effectiveness of novel nanocomposite of zinc-aluminum layered double hydroxide intercalated with gallic acid (GA) as chelating agent (Zn-Al LDH/GA) on the prevention and control of environmental pathogenic bacteria; Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumoniae), Staphylococcus aureus (S. aureus), and Coagulase-negative staphylococci (CNS), besides Listeria monocytogenes (L. monocytogenes) and assess the ability to use as an antimicrobial agent, and/or sanitizer for milking equipment. All samples (n = 230) involved clinical mastitis cow's milk (n = 50) beside environmental samples (n = 180) were collected then examined for isolation and identification of bacterial pathogens. Zn-Al LDH/GA nanocomposite was synthesized using co-precipitation method, then characterized by Fourier-transform infrared spectroscopy (FT-IR); X-ray diffraction (XRD); field emission scanning electron microscopy (FESEM); high-resolution transmission electron microscopy (HRTEM); thermogravimetric analysis (TGA); differential thermal analysis (DTA); zeta potential; DLS analysis; and Brunauer, Emmett, and Teller (BET) surface area. The anti-biofilm activity of nanocomposite against mastitis-causing bacteria was detected using the broth micro-dilution and disc-diffusion assay. Results, the minimum concentration of Zn-Al LDH/GA that inhibited the growth of gram-positive and negative bacteria, were 312-625 and 5000 μg/mL, respectively. The LD₅₀ of Zn-Al LDH/GA was determined in mice at 1983.3 mg/kg b.wt. As a conclusion, Zn-Al LDH/GA nanocomposite proved its efficiency as an antimicrobial agent and/or sanitizer used for cleaning of milking equipment, due to it could inhibit the growth and multiplication of potentially pathogenic bacteria that causing clinical mastitis and its formation of biofilm on the milking equipment. Zn-Al LDH/GA was found to use under varying pH conditions compared with other commercial sanitizer used besides the formation of nanocomposite increases the material stability.

Evaluation of multifunctional properties of gallic acid crosslinked Poly (vinyl alcohol)/Tragacanth Gum blend films for food packaging applications

The natural polymer Tragacanth Gum is less explored as a supporting matrix, there are very less studies conducted using this polymer in literature. So the present study aims to explore the consequences of different weight percent (wt.%) of gallic acid (GA) on physicochemical properties of Poly (vinyl alcohol)/Tragacanth Gum blend films. The incorporation of GA resulted in more strengthened but less flexible films as confirmed by tensile tests. DSC studies confirmed the miscibility of composite films in the given composition range and TGA studies revealed increased thermal stability. The morphological studies revealed a homogeneous distribution of GA at lower wt.% in the blend system. X-Ray Diffraction study depicted; the added GA lost crystalline structure after incorporating it into the blend. The Water Vapor Transmission Rate (WVTR) was improved after the incorporation of GA into the blend system. Overall migration studies revealed the limited release of GA from the matrix into food simulants. Soil degradation rate increased as the wt.% of GA increased. The composite films presented strong antioxidant activity; therefore, prepared composite films could be used as an alternative to current packaging materials.

Site-specific delivery of a natural chemotherapeutic agent to human lung cancer cells using biotinylated 2D rGO nanocarriers

Chemotherapy has remained one of the most commonly employed treatment modalities for cancer. Despite the clinical availability of a large number of chemotherapeutic agents, the uncontrolled systemic distribution and the associated harmful side effects of chemotherapeutic agents pose major challenges demanding concerted efforts to enhance their cancer targetability. The layered structure of two-dimensional (2D) materials offers new opportunities by increasing the drug pay-load influencing the drug-release kinetics in a cancer micro-environment and facilitating targetability through the large accessible surface area. To investigate such potential benefits of 2D materials, we have developed a biocompatible targeted 2D drug delivery system using graphene oxide (GO) as a model nanocarrier (NC) that could hold a high concentration of gallic acid (GA), a natural chemotherapeutic agent found in green tea. Interestingly, the antioxidant nature of GA also reduced GO to a high-quality few-layered thin reduced-graphene oxide (rGO) during drug loading while forming rGO nanocarrier (rGONC). The biotinylated rGONC further improved their targetability to A549 human lung carcinoma cells and they enhanced cellular internalization efficiency. From these targeted 2D NCs, the drug could release only slowly at the physiological pH but liberated rapidly at lower pH encountered by the tumor microenvironment resulting in significant toxicity toward the lung carcinoma cells. As such, this work opens up new possibilities for employing 2D materials for targeted chemotherapeutic applications.

Magnetically directed antioxidant and antimicrobial agent: synthesis and surface functionalization of magnetite with quercetin

Oxidative stress can be reduced substantially using nanoantioxidant materials by tuning its surface morphological features up to a greater extent. The physiochemical, biological and optical properties of the nanoantioxidants can be altered by controlling their size and shape. In view of that, an appropriate synthesis technique should be adopted with optimization of the process variables. Properties of magnetite nanoparticles (IONP) can be tailored to upgrade the performance of biomedicine. Present research deals with the functionalization IONP using a hydrophobic agent of quercetin (Q). The application of quercetin will control its size using both the functionalization method including in-situ and post-synthesis technique. In in-situ techniques, the functionalized magnetite nanoparticles (IONP@Q) have average particles size 6 nm which are smaller than the magnetite (IONP) without functionalization. After post functionalization technique, the average particle size of magnetite IONP@Q2 determined was 11 nm. The nanoparticles also showed high saturation magnetization of about 51-59 emu/g. Before starting the experimental lab work, Prediction Activity Spectra of Substances (PASS) software was used to have a preliminary idea about the biological activities of Q. The antioxidant activity was carried out using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. The antibacterial studies were carried out using well diffusion method. The results obtained were well supported by the simulated results. Furthermore, the values of the half maximal inhibitory concentration (IC50) of the DPPH antioxidant assay were decreased using the functionalized one and it exhibited a 2-3 fold decreasing tendency than the unfunctionalized IONP. This exhibited that the functionalization process can easily enhance the free radical scavenging properties of IONPs up to three times. MIC values confirms that functionalized IONP have excellent antibacterial properties against the strains used (Staphylococcus aureus, Bacillus subtilis and Escherichia coli) and fungal strains (Aspergillus niger, Candida albicans, Trichoderma sp. and Saccharomyces cerevisiae). The findings of this research showed that the synthesized nanocomposite has combinatorial properties (magnetic, antioxidant and antimicrobial) which can be considered as a promising candidate for biomedical applications. It can be successfully used for the development of biomedicines which can be subsequently applied as antioxidant, anti-inflammatory, antimicrobial and anticancer agents.

Synthesis and properties of magnetic nanotheranostics coated with polyethylene glycol/5-fluorouracil/layered double hydroxide

BACKGROUND

Cancer treatments are being continually developed. Increasingly more effective and better-targeted treatments are available. As treatment has developed, the outcomes have improved.

PURPOSE

In this work, polyethylene glycol (PEG), layered double hydroxide (LDH) and 5-fluorouracil (5-FU) were used as a stabilizing agent, a carrier and an anticancer active agent, respectively.

CHARACTERIZATION AND METHODS

Magnetite nanoparticles (Fe3O4) coated with polyethylene glycol (PEG) and co-coated with 5-fluorouracil/Mg/Al- or Zn/Al-layered double hydroxide were synthesized by co-precipitation technique. Structural, magnetic properties, particle shape, particle size and drug loading percentage of the magnetic nanoparticles were investigated by XRD, TGA, FTIR, DLS, FESEM, TEM, VSM, UV-vis spectroscopy and HPLC techniques.

RESULTS

XRD, TGA and FTIR studies confirmed the formation of Fe3O4 phase and the presence of iron oxide nanoparticles, polyethylene glycol, LDH and the drug for all the synthesized samples. The size of the nanoparticles co-coated with Mg/Al-LDH is about 27 nm compared to 40 nm when they were co-coated with Zn/Al-LDH, with both showings near uniform spherical shape. The iron oxide nanoparticles retain their superparamagnetic property when they were coated with polyethylene glycol, polyethylene glycol co-coated with Mg/Al-LDH and polyethylene glycol co-coated with Zn/Al-LDH with magnetic saturation value of 56, 40 and 27 emu/g, respectively. The cytotoxicity study reveals that the anticancer nanodelivery system has better anticancer activity than the free drug, 5-FU against liver cancer HepG2 cells and at the same time, it was found to be less toxic to the normal fibroblast 3T3 cells.

CONCLUSION

These are unique core-shell nanoparticles synthesized with the presence of multiple functionalities are hoped can be used as a multifunctional nanocarrier with the capability of targeted delivery using an external magnetic field and can also be exploited as hypothermia for cancer cells in addition to the chemotherapy property.

Delivery vehicle of muscle-derived irisin based on silk/calcium silicate/sodium alginate composite scaffold for bone regeneration

Background

Irisin is a cytokine produced by skeletal muscle and usually plays a pivotal role in inducing fat browning and regulating energy expenditure. In recent years, it was found that irisin might be the molecular entity responsible for muscle–bone connectivity and is useful in osteogenesis induction.

Materials and methods

To study its effect on bone regeneration, we developed silk/calcium silicate/sodium alginate (SCS) composite scaffold based on an interpenetrating network hydrogel containing silk fibroin, calcium silicate, sodium alginate. Then we loaded irisin on the SCS before coating it with polyvinyl alcohol (PVA). The SCS/P scaffold was physically characterized and some in vitro and in vivo experiments were carried out to evaluate the scaffold effect on bone regeneration.

Results

The SCS/P scaffold was showed a porous sponge structure pursuant to scanning electron microscopy analysis. The release kinetics assay demonstrated that irisin was stably released from the irisin-loaded hybrid system (i/SCS/P system) to 50% within 7 days. Moreover, osteoinductive studies using bone marrow stem cells (BMSCs) in vitro exhibited the i/SCS/P system improved the activity of alkaline phosphatase (ALP) and enhanced the expression levels of a series of osteogenic markers containing Runx-2, ALP, BMP2, Osterix, OCN, and OPN. Alizarin red staining also demonstrated the promotion of osteogenesis induced by i/SCS/P scaffolds. In addition, in vivo studies showed that increased bone regeneration with better mineralization and higher quality was found during the repair of rat calvarial defects through utilizing the i/SCS/P system.

Conclusion

These data provided strong evidence that the composite i/SCS/P would be a promising substitute for bone tissue engineering.

Improved Anticancer Effect of Magnetite Nanocomposite Formulation of GALLIC Acid (Fe₃O₄-PEG-GA) Against Lung, Breast and Colon Cancer Cells

Lung cancer, breast cancer and colorectal cancer are the most prevalent fatal types of cancers globally. Gallic acid (3,4,5-trihydroxybenzoic acid) is a bioactive compound found in plants and foods, such as white tea, witch hazel and it has been reported to possess anticancer, antioxidant and anti-inflammatory properties. In this study we have redesigned our previously reported anticancer nanocomposite formulation with improved drug loading based on iron oxide magnetite nanoparticles coated with polyethylene glycol and loaded with anticancer drug gallic acid (Fe₃O₄-PEG-GA). The in vitro release profile and percentage drug loading were found to be better than our previously reported formulation. The anticancer activity of pure gallic acid (GA), empty carrier (Fe₃O₄-PEG) nanocarrier and of anticancer nanocomposite (Fe₃O₄-PEG-GA) were screened against human lung cancer cells (A549), human breast cancer cells (MCF-7), human colon cancer cells (HT-29) and normal fibroblast cells (3T3) after incubation of 24, 48 and 72 h using (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) MTT assay. The designed formulation (Fe₃O₄-PEG-GA) showed better anticancer activity than free gallic acid (GA). The results of the in vitro studies are highly encouraging to conduct the in vivo studies.

Nano-Formulation of Ethambutol with Multifunctional Graphene Oxide and Magnetic Nanoparticles Retains Its Anti-Tubercular Activity with Prospects of Improving Chemotherapeutic Efficacy

Tuberculosis (TB) is a dreadful bacterial disease, infecting millions of human and cattle every year worldwide. More than 50 years after its discovery, ethambutol continues to be an effective part of the World Health Organization's recommended frontline chemotherapy against TB. However, the lengthy treatment regimens consisting of a cocktail of antibiotics affect patient compliance. There is an urgent need to improve the current therapy so as to reduce treatment duration and dosing frequency. In this study, we have designed a novel anti-TB multifunctional formulation by fabricating graphene oxide with iron oxide magnetite nanoparticles serving as a nano-carrier on to which ethambutol was successfully loaded. The designed nanoformulation was characterised using various analytical techniques. The release of ethambutol from anti-TB multifunctional nanoparticles formulation was found to be sustained over a significantly longer period of time in phosphate buffer saline solution at two physiological pH (7.4 and 4.8). Furthermore, the nano-formulation showed potent anti-tubercular activity while remaining non-toxic to the eukaryotic cells tested. The results of this in vitro evaluation of the newly designed nano-formulation endorse its further development in vivo.

Surface Functionalization of Iron Oxide Nanoparticles with Gallic Acid as Potential Antioxidant and Antimicrobial Agents

In this research, we report the size-controlled synthesis and surface-functionalization of magnetite with the natural antioxidant gallic acid (GA) as a ligand, using in situ and post-synthesis methods. GA functionalization provided narrow size distribution, with an average particle size of 5 and 8 nm for in situ synthesis of gallic acid functionalized magnetite IONP@GA1 and IONP@GA2, respectively, which are ultra-small particles as compared to unfunctionalized magnetite (IONP) and post functionalized magnetite IONP@GA3 with average size of 10 and 11 nm respectively. All the IONPs@GA samples were found hydrophilic with stable aggregation state. Prior to commencement of experimental lab work, PASS software was used to predict the biological activities of GA and it is found that experimental antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and antimicrobial studies using well diffusion method are in good agreement with the simulated results. Furthermore, the half maximal inhibitory concentration (IC50) values of DPPH antioxidant assay revealed a 2-4 fold decrease as compared to unfunctionalized IONP. In addition to antioxidant activity, all the three IONP@GA proved outstanding antimicrobial activity while testing on different bacterial and fungal strains. The results collectively indicate the successful fabrication of novel antioxidant, antimicrobial IONP@GA composite, which are magnetically separable, efficient, and low cost, with potential applications in polymers, cosmetics, and biomedical and food industries.

Gadolinium-Doped Gallic Acid-Zinc/Aluminium-Layered Double Hydroxide/Gold Theranostic Nanoparticles for a Bimodal Magnetic Resonance Imaging and Drug Delivery System

We have developed gadolinium-based theranostic nanoparticles for co-delivery of drug and magnetic resonance imaging (MRI) contrast agent using Zn/Al-layered double hydroxide as the nanocarrier platform, a naturally occurring phenolic compound, gallic acid (GA) as therapeutic agent, and Gd(NO₃)₃ as diagnostic agent. Gold nanoparticles (AuNPs) were grown on the system to support the contrast for MRI imaging. The nanoparticles were characterized using techniques such as Hi-TEM, XRD, ICP-ES. Kinetic release study of the GA from the nanoparticles showed about 70% of GA was released over a period of 72 h. The in vitro cell viability test for the nanoparticles showed relatively low toxicity to human cell lines (3T3) and improved toxicity on cancerous cell lines (HepG2). A preliminary contrast property test of the nanoparticles, tested on a 3 Tesla MRI machine at various concentrations of GAGZAu and water (as a reference) indicates that the nanoparticles have a promising dual diagnostic and therapeutic features to further develop a better future for clinical remedy for cancer treatment.

Using a bacterial fucose-rich polysaccharide as encapsulation material of bioactive compounds

The potential of a bacterial exopolysaccharide named FucoPol, produced by the bacterium Enterobacter A47, as encapsulation matrix was explored. Spherical capsules with a smooth surface were produced by spray drying. The obtained microcapsules had average diameters ranging from 0.5 to 26.7μm and presented thin walls (thickness from 222 to 1094nm). The capsules were loaded with two bioactive compounds: gallic acid (GA) and oregano essential oil (OEO). Both bioactive materials were encapsulated in FucoPol particles, retaining their antioxidant activity after the drying process. Release studies showed that GA release in simulated gastric and intestinal fluids was faster than that of OEO, envisaging that the latter had established stronger interactions with the polymer matrix. These results suggest that FucoPol has a good potential for use as encapsulating material of bioactive compounds for application in several areas, including food, cosmetic or pharmaceutical products.

Recent Advances in Anticancer Activities and Drug Delivery Systems of Tannins

Tannins, polyphenols in medicinal plants, have been divided into two groups of hydrolysable and condensed tannins, including gallotannins, ellagitannins, and (-)-epigallocatechin-3-gallate (EGCG). Potent anticancer activities have been observed in tannins (especially EGCG) with multiple mechanisms, such as apoptosis, cell cycle arrest, and inhibition of invasion and metastases. Furthermore, the combinational effects of tannins and anticancer drugs have been demonstrated in this review, including chemoprotective, chemosensitive, and antagonizing effects accompanying with anticancer effect. However, the applications of tannins have been hindered due to their poor liposolubility, low bioavailability, off-taste, and shorter half-life time in human body, such as EGCG, gallic acid, and ellagic acid. To tackle these obstacles, novel drug delivery systems have been employed to deliver tannins with the aim of improving their applications, such as gelatin nanoparticles, micelles, nanogold, liposomes, and so on. In this review, the chemical characteristics, anticancer properties, and drug delivery systems of tannins were discussed with an attempt to provide a systemic reference to promote the development of tannins as anticancer agents.

Graphene Oxide-Gallic Acid Nanodelivery System for Cancer Therapy

Despite the technological advancement in the biomedical science, cancer remains a life-threatening disease. In this study, we designed an anticancer nanodelivery system using graphene oxide (GO) as nanocarrier for an active anticancer agent gallic acid (GA). The successful formation nanocomposite (GOGA) was characterized using XRD, FTIR, HRTEM, Raman, and UV/Vis spectroscopy. The release study shows that the release of GA from the designed anticancer nanocomposite (GOGA) occurs in a sustained manner in phosphate-buffered saline (PBS) solution at pH 7.4. In in vitro biological studies, normal fibroblast (3T3) and liver cancer cells (HepG2) were treated with different concentrations of GO, GOGA, and GA for 72 h. The GOGA nanocomposite showed the inhibitory effect to cancer cell growth without affecting normal cell growth. The results of this research are highly encouraging to go further for in vivo studies.

Layered Double Hydroxide as a Vehicle to Increase Toxicity of Gallate Ions against Adenocarcinoma Cells

The antineoplasic activity of gallic acid has been reported. This compound induces apoptosis and inhibits the growth of several neoplasic cells. However, this molecule is easily oxidized and degraded in the body. The aim of this work was to intercalate gallate ions into layered double hydroxide (LDH) nanoparticles under controlled conditions to reduce oxidation of gallate and to evaluate its toxicity against the A549 adenocarcinoma cell line. An isopropanol medium under nitrogen atmosphere was adequate to intercalate gallate ions with a lesser oxidation degree as detected by electron spin resonance spectroscopy. Concentrations of the hybrid LDH-gallate nanoparticles between 0.39 and 25 µg/mL reduced the cell viability to 67%, while the value reached with the pure gallic acid and LDH was 90% and 78%, respectively, thus proving that the combination of gallate ions with the inorganic nanoparticles increases the toxicity potential within this dose range.

Encapsulation of Antioxidant Gallate Derivatives in Biocompatible Poly(ε-caprolactone)-b-Pluronic-b-Poly(ε-caprolactone) Micelles

Formulation of antioxidant agents is still a challenge that limits their application in the biomedical field. Pentablock copolymers obtained through modification of two common PEO-PPO-PEO copolymers (Pluronic F127 and F68) with poly(ε-carprolactone) (PCL) were evaluated regarding their capability to form nanocarriers suitable for gallic acid, methyl gallate, and ethyl gallate. Applying a dialysis method, PCL/F127/PCL and PCL/F68/PCL self-assembled into spherical micelles in 0.9% NaCl aqueous solution but notably differed in critical micellar concentration (CMC), micelle core hydrophobicity, and micelle size, as evidenced by pyrene fluorescence, transmission electron microscopy, and dynamic light scattering. Cytotoxicity studies showed that the copolymers were safe at concentrations well above the CMC. Transfer of gallic acid and derivatives from aqueous medium to the micelle phase was characterized in terms of distribution constant and free energy of transference, which were shown to be strongly dependent on the hydrophobicity of the gallate derivatives and the length of PCL in the pentablock copolymer. Antioxidant activity of gallates was challenged against DPPH previously loaded in PCL/F127/PCL and PCL/F68/PCL micelles. The more the hydrophobicity of the gallate derivative, the greater the capability to enter in the micelle and to consume free radicals. In vitro release studies of gallic acid, methyl gallate, and ethyl gallate from the pentablock copolymer micelles also evidenced the influence of the hydrophobicity of both the gallate derivative and the micelle core on release rate, recording a variety of release patterns. Overall, PCL/F127/PCL and PCL/F68/PCL appear as suitable nanocarriers of potent antioxidant agents in a wide range of polarities, which may be useful for diverse therapeutic applications.

Nano-antioxidants: An emerging strategy for intervention against neurodegenerative conditions

Oxidative stress has for long been linked to the neuronal cell death in many neurodegenerative conditions. Conventional antioxidant therapies have been less effective in preventing neuronal damage caused by oxidative stress due to their inability to cross the blood brain barrier. Nanoparticle antioxidants constitute a new wave of antioxidant therapies for prevention and treatment of diseases involving oxidative stress. It is believed that nanoparticle antioxidants have strong and persistent interactions with biomolecules and would be more effective against free radical induced damage. Nanoantioxidants include inorganic nanoparticles possessing intrinsic antioxidant properties, nanoparticles functionalized with antioxidants or antioxidant enzymes to function as an antioxidant delivery system. Nanoparticles containing antioxidants have shown promise as high-performance therapeutic nanomedicine in attenuating oxidative stress with potential applications in treating and preventing neurodegenerative conditions. However, to realize the full potential of nanoantioxidants, negative aspects associated with the use of nanoparticles need to be overcome to validate their long term applications.

SBA-15 Mesoporous Silica Modified with Gallic Acid and Evaluation of Its Cytotoxic Activity

Gallic acid has been covalently conjugated to SBA-15 mesoporous silica surface through different linkers. Cytotoxic activity of the hybrid organic-inorganic systems against HeLa and KB cell lines has been analyzed. Up to 67% of HeLa or KB tumor cells growth inhibition has been achieved at low silica concentration used (10 μg mL^-1).

Nanotechnology in drug delivery: the need for more cell culture based studies in screening

Advances in biomedical science are leading to upsurge synthesis of nanodelivery systems for drug delivery. The systems were characterized by controlled, targeted and sustained drug delivery ability. Humans are the target of these systems, hence, animals whose systems resembles humans were used to predict outcome. Thus, increasing costs in money and time, plus ethical concerns over animal usage. However, with consideration and planning in experimental conditions, in vitro pharmacological studies of the nanodelivery can mimic the in vivo system. This can function as a simple method to investigate the effect of such materials without endangering animals especially at screening phase.

Release behavior and toxicity profiles towards leukemia (WEHI-3B) cell lines of 6-mercaptopurine-PEG-coated magnetite nanoparticles delivery system

The coating of an active drug, 6-mercaptopurine, into the iron oxide nanoparticles-polyethylene glycol (FNPs-PEG) in order to form a new nanocomposite, FPEGMP-2, was accomplished using coprecipitation technique. The resulting nanosized with a narrow size distribution magnetic polymeric particles show the superparamagnetic properties with 38.6 emu/g saturation magnetization at room temperature. Fourier transform infrared spectroscopy and the thermal analysis study supported the formation of the nanocomposite and the enhancement of thermal stability in the resulting nanocomposite comparing with its counterpart in free state. The loading of 6-mercaptopurine (MP) in the FPEGMP-2 nanocomposite was estimated to be about 5.6% and the kinetic experimental data properly correlated with the pseudo-second order model. Also, the release of MP from the FPEGMP-2 nanocomposite shows the sustained release manner which is remarkably lower in phosphate buffered solution at pH 7.4 than pH 4.8, due to different release mechanism. The maximum percentage release of MP from the nanocomposite reached about 60% and 97% within about 92 and 74 hours when exposed to pH 7.4 and 4.8, respectively.