Papers by Keyword: Folic Acid

Abstract: Nanomedicine has been used in tumor treatment and research due to its advantages of targeting, controlled release and high absorption rate. Silver nanoparticle (AgNPs), with the advantages of small particle size, and large specific surface area, are of great potential value in suppressing and killing cancer cells. Methods: AgNPs–polyethyleneimine (PEI) –folate (FA) (AgNPs–PF) were synthesised and characterised by several analytical techniques. The ovarian cancer cell line Skov3 was used as the cell model to detect the tumor treatment activity of AgNPs, AgNPs–PF and AgNPs+ AgNPs–PF. Results: Results shown that AgNPs–PF were successfully constructed with uniform particle size of 50–70 nm. AgNPs, AgNPs–PF, AgNPs–PF+ AgNPs all showed a certain ability to inhibit cancer cell proliferation, increase reactive oxygen species and decrease the mitochondrial membrane potential. All AgNPs, AgNPs–PF, AgNPs+ AgNPs–PF promoted DNA damage in Skov3 cells, accompanied by the generation of histone RAD51 and γ-H2AX site, and eventually leading to the apoptosis of Skov3 cells. The combination of AgNPs–PF and AgNPs had a more pronounced effect than either material alone. Conclusion: This study is to report that the combination of AgNPs+ AgNPs–PF can cause stronger cytotoxicity and induce significantly greater cell death compared to AgNPs or AgNPs–PF alone in Skov3 cells. Therefore, the combined application of drugs could be the best way to cancer treatment.

Abstract: Gene therapy has great potential in offering highly promising treatments for cancer. Polymer-metal hybrid nanoparticles (NPs) are good candidates as gene delivery vehicles due to their unique properties and facile functionalization. The polymer component in hybrid NPs can provide accurate cancer cell targeting and high DNA binding ability while the metallic component can provide imaging functions for the nanodevices. In the present study, hybrid NPs comprising an Au-Ag bimetallic core and a folic acid-chitosan shell (Au-Ag@CS-FA) were fabricated. The structure and relevant properties of Au-Ag@CS-FA NPs were subsequently studied using a variety of techniques,like scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM) and UV-visible spectra. Their DNA binding ability was also assessed. Results showed that Au-Ag@CS-FA NPs possessed properties that can make them excellent gene delivery vehicles.

Abstract: This paper is mainly to investigate the stability of synthetic folic acid under different conditions, including pH, temperature, light, and the presence of antioxidants. The results show that folic acid gives a good stability in the buffer of pH 8.05~10.40, whose reservation ratio can reach more than 93.1% in 72 h, while the preservation ratio of folic acid reduce to 23% in the buffer of pH1.95~6.40. Moreover, folic acid has a good stability in the buffer of pH 5.39~10.40, after water bath at 100°C for 2 h. Folic acid exhibits a good stability under the condition of weak illumination intensity. Increasing illumination intensity promotes a decrease in FA concentration. The combination of antioxidants Vitamin C (VC) and sodium citrate displays a significant effect on protecting folic acid from oxidation.

Abstract: Folic acid-chitosan (FA-CTS) and 10-hydroxycamptothecin (HCPT)-loaded folate-conjugated chitosan (FA-CTS/HCPT) microspheres were prepared by the ionic crosslinking method.The morphological characteristics of microspheres were examined using a scanning electron microscope (SEM). The average particle size and size distribution were determined by dynamic light scattering. The drug encapsulation efficiency (EE) , loading capacity (LC)and release characteristics in vitro were determined using ultraviolet spectrophotometer.The results shown that the microspheres are uniform spherical and regular with a size between 19.79 and81.40μm.Optimized preparation parameters lead to the successful preparation of hydroxycamptothecin-loaded folate-conjugated chitosan microspheres characterized with encapsulation efficiency and loading capacity up to (86.8±0.1)% and 20.6±0.3 % respectively. More then 90% of 10-hydroxycamptothecin was released from microspheres in 4 h at artificial gastric juice, 8h at artificial small intestinal fluid with a good delayed release effect.

Abstract: FA-targeted and 10-hydroxycamptothecin loaded chitosan nanoparticles (FA-HCPT-NPs) were prepared with a combination of emulsion-solvent evaporation and chemical crosslink method. The analysis revealed that the FA-HCPT-NPs were spherical with diameter of 255.5  16.2 nm, zeta potential of + 70 mV, HCPT encapsulation efficiency of 81.2% and loading rate of 2.5%. X-ray powder diffraction illustrated that HCPT was buried as an amorphous form in the NPs. The release profiles of HCPT exhibited a biphasic pattern characterized by an initial burst release followed by a slower and sustained release. The results indicated that the novel FA-HCPT-NPs could be a potential drug delivery system for tumor cell-selective targeting therapy.

Abstract: This article is mainly to investigate the factors on the refining process of folic acid. The appropriate refining process (complex refining combined acid followed by alkali treatment) was proposed. The synthetic crude folic acid was treated firstly with sulfuric acid with the concentration of 30%, then re-purified with sodium hydroxide to give folic acid with the purity of 97% and total yield of 51.3%. Higher temperature (80-100°C) is desired for the crystallization of folic acid. The product treated in this process meets the requirements of CP, USP and BP.

Abstract: We prepared FA-targeted and 10-hydroxycamptothecin loaded chitosan nanoparticles (FA-HCPT-NPs) with a combination of emulsion-solvent evaporation and chemical crosslinking method. In vitro cytotoxicity test to the Human Cervix Carcinoma cells (HeLa) was evaluated by cell morphology and internalization observation. The specicity of the FA-HCPT-NPs targeting cancerous cells was demonstrated by comparative intracellular uptake of HCPT-NPs and commercial availible HCPT injection. Laser confocal scanning imaging proved that FA-HCPT-NPs could greatly enhance up-take by HeLa cells. The morphological changes of HeLa cells showed the FA-HCPT-NPs could inhibit HeLa cells more effectively than HCPT-NPs and HCPT. The results indicated that the novel FA-HCPT-NPs could be a potential drug delivery system for tumor cell-selective targeting therapy.

Abstract: Functionalized chitosan (CS) were widely used as drug delivery system in the chemotherapy of various disease. In this work, folate (FA) was conjugated into chitosan molecular as targeting ligand based on Schiff reaction between –NH₂ group of CS and –COOH group of FA. And nanoparticles were made by emulsion method with vanillin novel cross-linking agent. The FA modified CS and its nanoparticles were characterized by Fourier transform spectroscopy (FT-IR), scanning electron microscope (SEM) and Zeta potential. SEM results confirmed the nanoparticles made from FA-CS conjugate were spherical in shape and were about 100 nm in size. Zeta potential analysis revealed that the nanoparticles were negatively charged with charge density of -7.73mV.

Abstract: To make significant progress in the fight against cancer, treatment should target cells more specifically, produce fewer side effects, be easy to administer and deter tumor viability on multiple levels. We have attained dramatic in vivo tumor shrinkage and tumor vasculature disruption using a ternary biomolecular nanoparticle comprised of polymeric carrier polysaccharide heparin, anticancer drug retinoid and targeting ligand folic acid. The conjugation of retinoid and folic acid to heparin enhanced the water solubility of the drug, enabled selective targeting, and enhanced the role of heparin as anti-cancer drug carrier by eluding the coagulation cascade. This approach for targeting tumor holds great promise for treatment of various types of cancer. The folic acid linked heparin-retinoid conjugates (HFR) reactions was conjugated with ester and amide bonding which was confirmed by fourier transform infrared (FT-IR) and proton nuclear magnetic resonance (1H-NMR). The ratio of HFR conjugates was measured with Ultra-Violet spectrometry (UV-spectrometry). The particle size of HFR nanoparticles was measured by dynamic light scattering (DLS), and transmission electron microscopy (TEM). HFR conjugates were spherical and showed a diameter range of 200-300 nm in size. The nanoparticles maintained their stability in serum condition for 48hrs and have the high potential for applications in biomedical field.

Abstract: DP-bioglass is one of biodegradable glasses, which can be used as bioactive material in soft tissue and bone. It was often used in orthopedy and plastic surgery. Recently, bioglass was also used as a carrier for drug and gene delivery systems. Additionally, ferrimagnetic DP-bioglass can be potential candidates for magnetic induction hyperthermia, by using a magnetic field. The aim of this work is the preparation and characterization of surface-modified ferrimagnetic DP-bioglass. First DP-bioglass has to be surface-modified with polyethylene glycol (PEG) and folic acid (FA) to improve its intracellular uptake and ability to target specific cells. PEG-FA complex was synthesized using carbodiimide (DCC) to link PEG with FA. Then PEG-FA complex were immobilized on the surface of DP-bioglass by using amino-silane (AEAPS) as a coupling agent. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H NMR), and thermogravimetric analysis (TGA) was used to demonstrate this immobilization process. In biological study showed that immobilized ferromagnetic DP-bioglass with PEG-FA was non-cytotoxicity and significantly enhanced the intracellular uptake of DP-bioglass by target cells.