Synthesis of poly (amidoamine) (PAMAM) dendrimer-based chitosan for targeted drug delivery and cell therapy

Purpose: Gemcitabine is nucleoside analogue and used for various carcinomas like non-small cell lung cancer. Nanoparticle-based therapeutic agents have been developed for use in cancer therapy. Trimethyl chitosan TMC is methylated derivative of chitosan. TMC can be preferable because of the limited solubility of chitosan. Magnetic nanoparticles can be concentrated at cancerous tissue which provide targeted cancer therapy. In this study, we tried to develop and compare magnetically targeted trimethyl chitosan and chitosan nanoparticles for gemcitabine delivery in lung cancer therapy. Methods: Chitosan was trimethylated using methyl iodide. Magnetic nanoparticles were synthesized using co-precipitation method. TMC and chitosan nanoparticles were prepared by cross-linking method with tripolyphosphate. Gemcitabine was loaded onto nanoparticles via adsorption technique. After that characterization studies were performed and in vitro drug release tests were carried out. In order to determine cytotoxicites against A549-luc-C8 and CRL5809 cell lines, MTT assays were performed. Results and conclusion: Trimethylation of chitosan was verified with FTIR analysis. Gemcitabine was loaded with 54.7 and 30.3% on magnetic TMC nanoparticles and chitosan nanoparticles, respectively. According to drug release experiments, both carrier system had controlled drug release profile. IC50 values of gemcitabine loaded magnetic TMC nanoparticles were lower than that of magnetic chitosan nanoparticles. In conclusion, it was suggested that trimethyl chitosan nanoparticles had greater potential than chitosan nanoparticles for further analysis as a magnetically targeted therapy agent for lung cancer.

Composition and surface chemistry engineering of graphene grafting chitosan for stimuli-responsive cancer therapy: An in-silico study

Dendrimer functionalized magnetic nanoparticles as promising platforms for cancer theranostics

Introduction & Objective: Magnetic nanoparticles have found many applications because of their characteristics such as large surface area, small volume and simple separation with external magnetic field. These characteristics are very critical for drug delivery. In the current study, magnetic nanoparticles of iron oxide have been used as the central core of PAMAM dendrimer. The aim of current study was to evaluate the cytotoxic effects of this dandrimer on cancerous cell lines. Materials and methods: magnetic nanoparticles were synthesized through the co-precipitation method and its size was measured by an electron microscope. following, NH2 @ methyl acrylate + ethylintiamine groups were added as branches and hydroxyl group with the negative charge was placed on the end terminus of the dendrimer branchs. The size of the synthesized dendrimer was measured by SEM. In order to investigate the accuracy of the steric bond reaction between the ethylene diamine and methyl acrylate functional groups, a FTIR infrared absorption spectrometer was used to investigate the absorption peak in a range of 1720-1720 nm. In order to release the drug continuously, after loading the methyl Prednisolone drug onto a synthesized nano dendrimer, the entire collection was coated with chitosan quaternary derivative. The absorption spectrum of Prednisolone was measured at 284 nm wavelength (which is the maximum absorption peak) by the UV-visible light absorption device, and the amount of drug release was detected within 24 hours. Finally, the fatal effect of this nano-particle complex on the cancerous types GEJ-MCF 7 was investigated by inverse electron microscopy and the amount of nano-particle toxicity was measured using lactate dehydrogenase Kit and ELISA. Results: Based on the results of the electron microscope, the Fe3O4 size was in the range of 4.79 nm-6.37 nm range, which is smaller than nano-dendrimers with a range of 6.30 nm-43.67 nm. The FT-IR chart for the Methylacrylate @ Ethylendiamin esteric bond was obtained in the range of 1720 and 1730 cm -1. In this chart, the values of 600 cm-1 and 1000 cm-1 were related to Fe3O4 and Fe3O4 @ NH2, respectively. Triethyl Chitosan coated with Nanoparticle @ Drug coated with Nanoparticle @ Drug, along with trimethyl chitosan and glutaraldehyde creates a connection between TMC monomers. In this condition, glutaraldehyde helps to limit the delivery time of the drug. Also, cytotoxicity results indicated that the cell death rate in the incubated media with a complete nano-particle complex was dramatically greater than cell death rate with drug alone as well as nano-particle alone, which expresses the efficacy of the dendrimer-drug + chitosan drug complex. Conclusion: The results indicated that the synthesized nanoparticle complex by the proposed method increased the death rates in the studied cells. In addition, a low dose application of a drug in any nanoparticle compound reduces the side effects of drug, and this method is safe for cancer treatment.

Magnetic drug carriers: bright insights from light-responsive magnetic liposomes.

In this study, we prepare a biocompatible and magnetic material coated with dopamine (Fe3O4/SiO2@DA) for drug delivery of doxorubicin. Doxorubicin is a commercially available drug for the treatment of several types of cancers such as metastatic breast carcinoma, blood, lungs, ovarian carcinoma, and sarcoma. Magnetic nanoparticles are synthesized by co-precipitation method and coated with dopamine. Characterization of materials is carried out by Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Magnetic properties of the particles are evaluated by magnetic moment measurements. Later, this material is applied to the targeted delivery of doxorubicin. Several experimental parameters such as loading time, release time, loading temperature, release temperature, desorption pH, amount of nanomaterial, salt concentration, and effect of solvent are optimized. Loading of a drug is maximum in basic pH while acidic pH (3.3) works best for the desorption process. With increasing the amount of material, loading of drug increase. Moreover, salt (NaCl) concentration does not affect the loading process. Loading of a drug is maximum at a lower temperature (room temperature) while the release is more efficient at a higher temperature (40–45 °C). This material showed superior efficiency (drug loading, drug release, and time) as compared to previously reported similar materials. These results indicate that Fe3O4/SiO2@DA has excellent potential to carry the drug and deliver to cancerous cells which have acidic pH and higher temperature as compared to normal healthy cells.

Trimethyl chitosan (TMC) has demonstrated effectiveness as an absorption enhancer for hydrophilic and high molecular weight (MW) drugs across the intestinal epithelium. However, the effects of degrees of quaternization (DQ) of TMC on the absorption of negatively and positively charged drugs have not been investigated. This investigation aimed to determine the properties of the tablets formulated using TMC with different DQ. In this study, TMC with DQ of 20 % (TMC-20), 40 % (TMC-40) and 60 % (TMC-60) were synthesized and subsequently characterized. Cetirizine dihydrochloride (CHC) and hyoscine butylbromide (HBB) were used as negatively and positively charged model drugs. Eight tablet formulations were prepared using the wet granulation method. The formulated tablets were evaluated regarding their properties in terms of thickness and hardness, weight variation, disintegration time, and dissolution profile. These tablets were evaluated according to the standards set by the United States Pharmacopeia (USP41) guidelines. The results showed that TMC with all DQ have the MW and an intrinsic viscosity less than starting chitosan. The MW and an intrinsic viscosity of the synthesized TMC decreased with increasing DQ. In order to evaluate the effect of TMC with various DQ on the properties of the formulated tablets, all tablet formulations prepared had good characteristics and were found to be within the acceptable range based on the requirements of USP. In conclusion, TMC had a minor retarding effect on the dissolution profiles of CHC from the formulated tablets. Still, TMC was able to significantly delay the release of HBB from the formulated tablets (p > 0.05). When TMC with various DQ were compared, TMC-60 showed higher drug release than TMC-20 and TMC-40. In our study, we observed a possible interaction between the model drugs and TMC. This warrants the need for further studies. HIGHLIGHTS Degree of quaternization represents the charge density of trimethyl chitosan (TMC) Degradation of the polymer backbone occurred in the synthesis reaction step TMC affects dissolution profiles of a negative charged drug Ionic interaction and viscous gel layer of TMC affects the model drug release

Nanotechnology has ushered in significant advancements in drug design, revolutionizing the prevention, diagnosis, and treatment of various diseases. The strategic utilization of nanotechnology to enhance drug loading, delivery, and release has garnered increasing attention, leveraging the enhanced physical and chemical properties offered by these systems. Polyamidoamine (PAMAM) dendrimers have been pivotal in drug delivery, yet there is room for further enhancement. In this study, we conjugated PAMAM dendrimers with chitosan (CS) to augment cellular internalization in tumor cells. Specifically, doxorubicin (DOX) was initially loaded into PAMAM dendrimers to form DOX-loaded PAMAM (DOX@PAMAM) complexes via intermolecular forces. Subsequently, CS was linked onto the DOX-loaded PAMAM dendrimers to yield CS-conjugated PAMAM loaded with DOX (DOX@CS@PAMAM) through glutaraldehyde crosslinking via the Schiff base reaction. The resultant DOX@CS@PAMAM complexes were comprehensively characterized using Fourier-transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and dynamic light scattering (DLS). Notably, while the drug release profile of DOX@CS@PAMAM in acidic environments was inferior to that of DOX@PAMAM, DOX@CS@PAMAM demonstrated effective acid-responsive drug release, with a cumulative release of 70% within 25 h attributed to the imine linkage. Most importantly, DOX@CS@PAMAM exhibited significant selective cellular internalization rates and antitumor efficacy compared to DOX@PAMAM, as validated through cell viability assays, fluorescence imaging, and flow cytometry analysis. In summary, DOX@CS@PAMAM demonstrated superior antitumor effects compared to unconjugated PAMAM dendrimers, thereby broadening the scope of dendrimer-based nanomedicines with enhanced therapeutic efficacy and promising applications in cancer therapy.

Designing magnetic graphene oxide-polymer nanocomposites for pH-responsive passive targeting of hydrophobic anticancer drug 5-fluorouracil for breast cancer therapy.

DNA and viruses are biological building blocks that in recent year have also been used to create new nanomaterials with applications in material science, nanomedicine and bio-nanotechnology. DNA nanostructures (DNs) have been used, for example, as promising drug carriers owing to their properties related to drug loading efficiency, controlled drug release mechanisms, biocompatibility and surface functionalisation. However, the literature suggests some significant challenges for the use of DNs in effective and targeted drug delivery such as their stability against nuclease digestion and increasing their circulation half-life in the cellular environments. In order to tackle the challenges mentioned above, virus capsids can be often used to coat the DN’s surface, facilitating their entry into cells. Such surface-modified DNs exhibit also improved stability and low non-specific interactions in the cellular milieu. Thus, creating multifunctional biohybrid nanocarriers from DN and virus proteins capable of targeting specific cells and ensure stimuli-responsive drug release is of great utility in therapeutic applications. The main objective of this research project was to create ‘smart’ nanocarriers by coating drug-loaded modular DNs with viral capsid proteins (CP), isolated from the cowpea chlorotic mottle virus (CCMV). Four modular DNs were designed and validated in-silico using designing and structure prediction softwares. DNs were then self-assembled using a bottom-up approach and characterised using electrophoresis and imaging techniques. Next, two purified DNs were coated with virus capsid proteins forming assemblies at neutral pH and tested as potential delivery vehicles. Imaging of encapsulated assemblies showed the presence of a “protein corona” around the DNs, confirming the formation of encapsulated DNs with CPs. One of the critical parameters in the encapsulation process is the DN-CP interaction, which was studied as a CP:DNA mass ratio and successful encapsulation of DNs was only reported at only increased ratios. The resulting nano-assemblies were found to be monodisperse with an average particle size between 40-50 nm. Following the formation of nanoassemblies, anthracycline daunorubicin, a chemotherapeutic drug was incorporated into two selected DNs and evaluated for their drug-loading efficiency. DNs were then, encapsulated with CPs to form a functional drug-loaded nanocarrier. The resulting nanocarriers were purified and characterised for monitoring the structural modification with analytical techniques. Next, the stability and drug-releasing properties of the nanocarriers were investigated, towards time-dependent controlled drug delivery at the target site. The formulated CP-coated nanocarriers were observed to outperform uncoated DNs and unfolded ds-DNA in stability studies against enzymatic degradation. The designed nanocarriers were also evaluated for their drug retention properties and were found to be capable of transporting a large amount of drug inside cells. Additionally, the triggered drug release within the cellular environment marked the utility of the created nanocarriers in delivery, indicating its potential in biomedical applications. Furthermore, to study the anticancer therapeutic efficacy, the intracellular fate of these nanocarriers was studied. Drug-loaded and CP-encapsulated DNs were tested in pancreatic cancer cell lines (PANC-1) for their cellular viability and drug uptake. Nanocarriers were found to prefer the clathrin-mediated endocytosis as the main uptake route, and their cellular internalisation kinetics appears to be size and cell-type dependent. Moreover, nanocarriers were identified to be endocytosed by cells after 2 hours of incubation and attain a controlled drug-release state with a protein coating on their surface, thereby facilitating drug enrichment inside cancer cells. Overall, we successfully demonstrated the potential of using Drug/DNs-virus hybrid nanoassemblies as smart drug nanocarriers. The designed nanocarriers were reported to mimic the morphology and functionality of virus-like particles with increased stability, enhanced cellular uptake, and efficiently targeting the cancer cells. DNs provide a robust platforms for delivering chemotherapeutic agents into cancer cells. However, extending the horizon of using these designed DNs-based nanocarriers in cancer therapeutics requires more in -vitro and in- vivo studies sweeping various cancer cell lines. Hence, the results presented in this thesis form a factual basis for further research using self-assembled biohybrid materials in cancer theranostics and drug delivery. There lie different opportunities to synchronise the properties of two biomolecules and investigate their use in a wide range of other biomedical applications. Thus, on a lighter note, we can say all viruses are not dreadful, but few eventually make us better instead.

The convergence of in silico approach and nanomedicine for efficient cancer treatment; in vitro investigations on curcumin loaded multifunctional graphene oxide nanocomposite structure

Context: Polyamidoamine (PAMAM) dendrimers have attracted lots of interest as drug carriers. And little study about whether pluronic-attached PAMAM dendrimers could be potential drug delivery systems has been carried on.Objective: Pluronic F127 (PF127) attached PAMAM dendrimers were designed as novel drug carriers.Methods: Two conjugation ratios of PF127-attached PAMAM dendrimers were synthesized. 1H nuclear magnetic resonance (1H-NMR), Fourier transform infrared spectrum (FTIR), element analysis and ninhydrin assay were used to characterize the conjugates. Size, zeta potential and critical micelle concentrations (CMC) were also detected. And DOX was incorporated into the hydrophobic interior of the conjugates. Studies on their drug loading and drug release were carried on. Furthermore, hemolysis and cytotoxicity assay were used to evaluate the toxicity of the conjugates.Results and discussion: PF127 was successfully conjugated to the fifth generation PAMAM dendrimer at two molar ratios of 19% and 57% (PF127 to surface amine per PAMAM dendrimer molecular). The conjugates showed an increased size and a reduced zeta potential. And higher CMC values were obtained than pure PF127. Compared with unconjugated PAMAM dendrimer, PF127 conjugation significantly reduced the hemolytic toxicity and cytotoxicity of PAMAM dendrimer in vitro. The encapsulation results showed that the ability to encapsulate DOX by the conjugate of 19% conjugation ratio was better than that of 57% conjugation ratio. And the maximum is ∼12.87 DOX molecules per conjugate molecule. Moreover, the complexes showed a sustained release behavior compared to pure DOX.Conclusion: Findings from the in vitro study show that the PF127-attached PAMAM dendrimers may be potential carriers for drug delivery.

Sodium alginate–polyvinyl alcohol–bovin serum albumin coated Fe3O4 nanoparticles as anticancer drug delivery vehicle: Doxorubicin loading and in vitro release study and cytotoxicity to HepG2 and L02 cells

Background: Nanocomposites are of great interest due to their competency to show multifunctional properties. They have been recently given much attention due to their credibility to offer the synergistic feature of organic material with those of inorganic constituents. Different types of nanocomposites have been prepared to date and are being used for different applications. The delivery of drugs in the human body at a particular site was one of the major problems in the medicinal field. The nanocomposite formulations can be used to provide controlled release and they can be combined with ligands for targeted drug delivery. Applications of the nanocomposites as ion exchangers are also increasing at a faster rate. Due to this, they help in the softening of the water. They can also be easily recharged by washing them with a solution containing a high concentration of sodium ions. In the present paper, we have worked on the synthesis and applications of the polysorbate/ironmolybdophosphate (PS/FMP) nanocomposite. Methods: Polysorbate/ironmolybdophosphate (PS/FMPS) was synthesized by co-precipitation method in the presence of polysorbate. The material was well characterized using X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy, (FTIR) scanning transmission microscopy (SEM), and transmission electron microscopy (TEM). Physicochemical properties of material were studied in detail. Drug delivery behavior of polysorbate/ironmolybdophosphate was investigated by using methylcobalamin as a test drug. Results: The polysorbate/ironmolybdophosphate nanocomposite show enhanced Na+ ion exchange capacity of 2.1 meq/g. It has been revealed that PS/FMP nanocomposite was thermally stable as it retained the ion exchange capacity of 40.4 % at 400°C. An optimum concentration of sodium nitrate (eluent) was found to be 1.0 M for the complete removal of H+ ions from the PS/FMP column. The optimum volume of sodium nitrate (eluent) was found to be 230 mL. The FTIR spectra showed the changes in intensities of characteristic peaks in PS/FMP and in drug loaded on PS/FMP nanocomposite. The characteristic peak at 1043-1061 cm-1 was observed for ionic phosphate stretching, 560-567 cm-1 for iron group and 959 cm-1 due to molybdate present in the material. The additional peak at 3390 cm-1 and 1711 cm-1 were due to -OH and C=O stretching due to the presence of these groups in the structure of polysorbate. The peak present at 430 cm-1 might be due to the presence of Co-O stretching of methylcobalamin. The XRD results confirmed the semicrystalline structure of FMP and PS/FMP. Scanning electron micrographs results revealed the beaded surface of FMP changes to fibrous surface in case of PS/FMP nanocomposite. The TEM images indicate the appearance of smooth surfactant layer on the surface of FMP. The size of the nanocomposite is between 10- 70 nm. The drug loading efficiency and encapsulation efficiency were found to be 35.2%. and 60.4%, respectively. The cumulative drug release of methylcobalamin was studied for the PS/FMP nanocomposite. The order of drug release was found to be pH 9.4 (54.6%) > pH 7.4 (46.4%) > saline (pH 5.7) (36.2%) > pH 2.2 (33.9%). The release at pH 9.4 was higher. As the pH of medium changes from acidic to basic i.e. 2.2 - 9.4, there is an appreciable increase in drug release from the PS/FMP nanocomposite due to the presence of more OH- ions resulting in neutralization of cationic nanocomposite and thus increasing the rate of drug release by ion exchange process and matrix deterioration. : The novel nanocomposite PS/FMP has been synthesized by a simple co-precipitation method. The increase in Na+ ion exchange capacity for nanocomposite is due to the binding of organic part (Polysorbate) with inorganic ironmolybdophosphate. The physiochemical properties of PS/FMP were found to be superior. Fourier transform infrared spectra of PS/FMP and drug loaded PS/FMP confirmed the formation of materials. The SEM results indicated the surface of synthesized FMP is bead-like appearance whereas the beaded surface of FMP changes to fibrous surface on the addition of polysorbate thus indicated the fabrication of nanocomposite. The cumulative drug release of methylcobalamin was studied and the order of drug release was found to be pH 9.4 > pH 7.4 > saline (pH 5.7) > pH 2.2. Thus PS/FMP is a promising multifunctional nanocomposite.

The effect of using albumin-perfluorohexane/cisplatin-magnetite nanoparticles produced by hydrothermal method against gastric cancer cells through combination therapy