Evaluation of cytotoxicity profile and intracellular localisation of doxorubicin-loaded chitosan nanoparticles

Fabrication of folic acid-conjugated pyrimidine-2(5H)-thione-encapsulated curdlan gum-PEGamine nanoparticles for folate receptor targeting breast cancer cells

In this study 5-((2-((3-methoxy benzylidene)-amino)-phenyl)-diazenyl)-4,6-diphenyl pyrimidine-2(5H)-thione was synthesized. The pharmacological applications of pyrimidine analogs are restricted due to their poor pharmacokinetic properties. As a solution, a microbial exopolysaccharide (curdlan gum) was used to synthesize folic acid-conjugated pyrimidine-2(5H)-thione-encapsulated curdlan gum-PEGamine nanoparticles (FA-Py-CG-PEGamine NPs). The results of physicochemical properties revealed that the fabricated FA-Py-CG-PEGamine NPs were between 100 and 400 nm in size with a majorly spherical shaped, crystalline nature, and the encapsulation efficiency and loading capacity were 79.04 ± 0.79 %, and 8.12 ± 0.39 % respectively. The drug release rate was significantly higher at pH 5.4 (80.14 ± 0.79 %) compared to pH 7.2. The cytotoxic potential of FA-Py-CG-PEGamine NPs against MCF-7 cells potentially reduced the number of cells after 24 h with 42.27 μg × mL-1 as IC50 value. The higher intracellular accumulation of pyrimidine-2(5H)-thione in MCF-7 cells leads to apoptosis, observed by AO/EBr staining and flow cytometry analysis. The highest pyrimidine-2(5H)-thione internalization in MCF-7 cells may be due to folate conjugated on the surface of curdlan gum nanoparticles. Further, internalized pyrimidine-2(5H)-thione increases the intracellular ROS level, leading to apoptosis and inducing the decalin in mitochondrial membrane potential. These outcomes demonstrated that the FA-Py-CG-PEGamine NPs were specificity-targeting folate receptors on the plasma membranes of MCF-7 Cells.

Co-delivery of carboplatin and doxorubicin using ZIF-8 coated chitosan-poly(N-isopropyl acrylamide) nanoparticles through a dual pH/thermo responsive strategy to breast cancer cells

A dual pH/temperature sensitive core-shell nanoformulation has been developed based on ZIF-8 coated with chitosan-poly(N-isopropyl acrylamide) (CS-PNIPAAm) for co-delivery of doxorubicin (DOX) and carboplatin (CBP) in breast cancer cells. The resulting nanoparticles (NPs) had particle sizes around 200 nm and a zeta potential of about +30 mV. The CBP and DOX loading contents in the final NPs were 11.6 % and 55.54 %, respectively. NPs showed a pH and thermoresponsive drug release profile with a sustained prolonged release under physiological conditions. The in vitro cytotoxicity experiments showed a significant synergism of CBP and DOX to induce the IC50 of 1.96 μg/mL in MCF-7 cells and 4.54 μg/mL in MDA-MB-231 cells. Also, the final NPs were safer than free DOX and CBP on normal cells. The in vitro study confirmed the higher potency of the designed NPs in combination therapy against breast cancer cells with lower side effects than free drugs.

Optimized DOX Drug Deliveries via Chitosan-Mediated Nanoparticles and Stimuli Responses in Cancer Chemotherapy: A Review

Chitosan nanoparticles (NPs) serve as useful multidrug delivery carriers in cancer chemotherapy. Chitosan has considerable potential in drug delivery systems (DDSs) for targeting tumor cells. Doxorubicin (DOX) has limited application due to its resistance and lack of specificity. Chitosan NPs have been used for DOX delivery because of their biocompatibility, biodegradability, drug encapsulation efficiency, and target specificity. In this review, various types of chitosan derivatives are discussed in DDSs to enhance the effectiveness of cancer treatments. Modified chitosan-DOX NP drug deliveries with other compounds also increase the penetration and efficiency of DOX against tumor cells. We also highlight the endogenous stimuli (pH, redox, enzyme) and exogenous stimuli (light, magnetic, ultrasound), and their positive effect on DOX drug delivery via chitosan NPs. Our study sheds light on the importance of chitosan NPs for DOX drug delivery in cancer treatment and may inspire the development of more effective approaches for cancer chemotherapy.

The first facile optical density-dependent approach for the analysis of doxorubicin, an oncogenic agent accompanied with the co-prescribed drug; paclitaxel

Doxorubicin (DRB) is an anthracycline oncogenic drug extracted from cultures of Streptomyces peucetius var. caesius. It is frequently recommended as an anti-neoplastic agent for the treatment of diverse malignancies. It exerts its antineoplastic effect either via inhibiting the enzyme topoisomerase II and/or via intercalation to DNA or reactive oxygen species generation. In the present article, the direct, simple, one-pot, somewhat eco-safe, and non-extractive spectrophotometric system was executed to track doxorubicin, a chemotherapeutic remedy, in the presence of paclitaxel, a naturally occurring Taxan antineoplastic radical, through the greenness rated method. DRB's optical density was studied in various mediums and solvents to develop the current approach. An acidic ethanolic solution was found to increase the optical density of the sample significantly. At 480 nm., the most remarkable optical density was obtained. Various experimental factors, including intrinsic media, solvent, pH, and stability time, were investigated and controlled. The current approach achieved linearity within the 0.6-40.0 µg mL-1 range, accompanied by a limit of both detection and quantification (LOD and LOQ) of 0.18 and 0.55 µg mL-1, correspondingly. The approach was validated under the ICH guidelines (Quality Guidelines). The system's greenness and enhancement degree were estimated.

Combining Pharmacokinetics and Vibrational Spectroscopy: MCR-ALS Hard-and-Soft Modelling of Drug Uptake In Vitro Using Tailored Kinetic Constraints

Raman microspectroscopy is a label-free technique which is very suited for the investigation of pharmacokinetics of cellular uptake, mechanisms of interaction, and efficacies of drugs in vitro. However, the complexity of the spectra makes the identification of spectral patterns associated with the drug and subsequent cellular responses difficult. Indeed, multivariate methods that relate spectral features to the inoculation time do not normally take into account the kinetics involved, and important theoretical information which could assist in the elucidation of the relevant spectral signatures is excluded. Here, we propose the integration of kinetic equations in the modelling of drug uptake and subsequent cellular responses using Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) and tailored kinetic constraints, based on a system of ordinary differential equations. Advantages of and challenges to the methodology were evaluated using simulated Raman spectral data sets and real Raman spectra acquired from A549 and Calu-1 human lung cells inoculated with doxorubicin, in vitro. The results suggest a dependency of the outcome on the system of equations used, and the importance of the temporal resolution of the data set to enable the use of complex equations. Nevertheless, the use of tailored kinetic constraints during MCR-ALS allowed a more comprehensive modelling of the system, enabling the elucidation of not only the time-dependent concentration profiles and spectral features of the drug binding and cellular responses, but also an accurate computation of the kinetic constants.

High-Throughput Method for the Simultaneous Determination of Doxorubicin Metabolites in Rat Urine after Treatment with Different Drug Nanoformulations

Doxorubicin (DOX) is one of the most effective cytotoxic agents against malignant diseases. However, the clinical application of DOX is limited, due to dose-related toxicity. The development of DOX nanoformulations that significantly reduce its toxicity and affect the metabolic pathway of the drug requires improved methods for the quantitative determination of DOX metabolites with high specificity and sensitivity. This study aimed to develop a high-throughput method based on high-performance liquid chromatography with fluorescence detection (HPLC-FD) for the quantification of DOX and its metabolites in the urine of laboratory animals after treatment with different DOX nanoformulations. The developed method was validated by examining its specificity and selectivity, linearity, accuracy, precision, limit of detection, and limit of quantification. The DOX and its metabolites, doxorubicinol (DOXol) and doxorubicinone (DOXon), were successfully separated and quantified using idarubicin (IDA) as an internal standard (IS). The linearity was obtained over a concentration range of 0.05–1.6 μg/mL. The lowest limit of detection and limit of quantitation were obtained for DOXon at 5.0 ng/mL and 15.0 ng/mL, respectively. For each level of quality control (QC) samples, the inter- and intra-assay precision was less than 5%. The accuracy was in the range of 95.08–104.69%, indicating acceptable accuracy and precision of the developed method. The method was applied to the quantitative determination of DOX and its metabolites in the urine of rats treated by novel nanoformulated poly(lactic-co-glycolic acid) (DOX-PLGA), and compared with a commercially available DOX solution for injection (DOX-IN) and liposomal-DOX (DOX-MY).

Synthesis, characterization and application of chitosan-N-(4-hydroxyphenyl)-methacrylamide derivative as a drug and gene carrier

The aim of this study was to develop a green method to fabricate a novel CS modified N-(4-hydroxyphenyl)- methacrylamide conjugate (CSNHMA) and to evaluate its biomedical potential. CSNHMA has been prepared by a simple method via aza Michael addition reaction between CS and N- (4-hydroxyphenyl)-methacrylamide (NHMA) in ethanol. Its structural and morphological properties were characterized by various analysis techniques. The obtained results confirmed that a highly porous network structure of CSNHMA was successfully synthesized via aza Michael addition reaction. Consequently, it was analyzed as a drug and gene carrier. CSNHMA/pGL3 showed an enhanced buffering capacity due to the presence of NHMA moiety leading to higher transfection efficiency in all cancer cells (A549, HeLa and HepG2) as compared to native CS and Lipofectamine®. Therefore, these findings clearly support the possibility of using CSNHMA as a good transfection agent. For in vitro drug release study, we prepared CSNHMA nanoparticles (NPs) and curcumin loaded CSNHMA NPs of size <230 nm respectively via the non-toxic ionic gelation route and the encapsulation efficiency of drug was found to be 77.03%. In vitro drug release studies demonstrated a faster and sustained release of curcumin loaded CSNHMA NPs at pH 5.0 compared to physiological pH.

Targeted doxorubicin delivery and release within breast cancer environment using PEGylated chitosan nanoparticles labeled with monoclonal antibodies

Breast cancer has been one of the top chronic and life-threatening diseases worldwide. Nano-drug therapeutic systems have proved their efficacy as a selective treatment compared to the traditional ones that are associated with serious adverse effects. Here, biodegradable chitosan nanoparticles (CSNPs) were synthesized to provide selective and sustained release of doxorubicin (DOX) within the breast tumor microenvironment. CSNPs surface was modified using Polyethylene glycol (PEG) to enhance their blood circulation timing. To provide high drug selectivity, CSNPs functionalized with two different types of breast cancer-specific monoclonal antibodies (mAb); anti-human mammaglobin (Anti-hMAM) and anti-human epidermal growth factor (Anti-HER2). Anti-hMAM PEGylated DOX loaded CSNPs and Anti-HER2 PEGylated DOX loaded CSNPs nano-formulations were the most cytotoxic against MCF-7 cancer cells than L-929 normal cells compared to free DOX. Finally, we believe that dose-dependent system toxicity of freely ingested DOX can be managed with such targeted nano-formulated drug delivery platforms.

Biomimetic Aspects of Oral and Dentofacial Regeneration

Biomimetic materials for hard and soft tissues have advanced in the fields of tissue engineering and regenerative medicine in dentistry. To examine these recent advances, we searched Medline (OVID) with the key terms “biomimetics”, “biomaterials”, and “biomimicry” combined with MeSH terms for “dentistry” and limited the date of publication between 2010–2020. Over 500 articles were obtained under clinical trials, randomized clinical trials, metanalysis, and systematic reviews developed in the past 10 years in three major areas of dentistry: restorative, orofacial surgery, and periodontics. Clinical studies and systematic reviews along with hand-searched preclinical studies as potential therapies have been included. They support the proof-of-concept that novel treatments are in the pipeline towards ground-breaking clinical therapies for orofacial bone regeneration, tooth regeneration, repair of the oral mucosa, periodontal tissue engineering, and dental implants. Biomimicry enhances the clinical outcomes and calls for an interdisciplinary approach integrating medicine, bioengineering, biotechnology, and computational sciences to advance the current research to clinics. We conclude that dentistry has come a long way apropos of regenerative medicine; still, there are vast avenues to endeavour, seeking inspiration from other facets in biomedical research.

Cold Atmospheric Plasma Stimulates Clathrin-Dependent Endocytosis to Repair Oxidised Membrane and Enhance Uptake of Nanomaterial in Glioblastoma Multiforme Cells

Cold atmospheric plasma (CAP) enhances uptake and accumulation of nanoparticles and promotes synergistic cytotoxicity against cancer cells. However, the mechanisms are not well understood. In this study, we investigate the enhanced uptake of theranostic nanomaterials by CAP. Numerical modelling of the uptake of gold nanoparticle into U373MG Glioblastoma multiforme (GBM) cells predicts that CAP may introduce a new uptake route. We demonstrate that cell membrane repair pathways play the main role in this stimulated new uptake route, following non-toxic doses of dielectric barrier discharge CAP. CAP treatment induces cellular membrane damage, mainly via lipid peroxidation as a result of reactive oxygen species (ROS) generation. Membranes rich in peroxidised lipids are then trafficked into cells via membrane repairing endocytosis. We confirm that the enhanced uptake of nanomaterials is clathrin-dependent using chemical inhibitors and silencing of gene expression. Therefore, CAP-stimulated membrane repair increases endocytosis and accelerates the uptake of gold nanoparticles into U373MG cells after CAP treatment. We demonstrate the utility of CAP to model membrane oxidative damage in cells and characterise a previously unreported mechanism of membrane repair to trigger nanomaterial uptake. This knowledge will underpin the development of new delivery strategies for theranostic nanoparticles into cancer cells.

Nanoparticle Delivery Systems in the Treatment of Diabetes Complications

Diabetes mellitus, an incurable metabolic disease, is characterized by changes in the homeostasis of blood sugar levels, being the subcutaneous injection of insulin the first line treatment. This administration route is however associated with limited patient's compliance, due to the risk of pain, discomfort and local infection. Nanoparticles have been proposed as insulin carriers to make possible the administration of the peptide via friendlier pathways without the need of injection, i.e., via oral or nasal routes. Nanoparticles stand for particles in the nanometer range that can be obtained from different materials (e.g., polysaccharides, synthetic polymers, lipid) and are commonly used with the aim to improve the physicochemical stability of the loaded drug and thereby its bioavailability. This review discusses the use of different types of nanoparticles (e.g., polymeric and lipid nanoparticles, liposomes, dendrimers, niosomes, micelles, nanoemulsions and also drug nanosuspensions) for improved delivery of different oral hypoglycemic agents in comparison to conventional therapies.

Biomaterials and Scaffold Design Strategies for Regenerative Endodontic Therapy

Challenges with traditional endodontic treatment for immature permanent teeth exhibiting pulp necrosis have prompted interest in tissue engineering approaches to regenerate the pulp-dentin complex and allow root development to continue. These procedures are known as regenerative endodontic therapies. A fundamental component of the regenerative endodontic process is the presence of a scaffold for stem cells from the apical papilla to adhere to, multiply and differentiate. The aim of this review is to provide an overview of the biomaterial scaffolds that have been investigated to support stem cells from the apical papilla in regenerative endodontic therapy and to identify potential biomaterials for future research. An electronic search was conducted using Pubmed and Novanet databases for published studies on biomaterial scaffolds for regenerative endodontic therapies, as well as promising biomaterial candidates for future research. Using keywords "regenerative endodontics," "scaffold," "stem cells" and "apical papilla," 203 articles were identified after duplicate articles were removed. A second search using "dental pulp stem cells" instead of "apical papilla" yielded 244 articles. Inclusion criteria included the use of stem cells from the apical papilla or dental pulp stem cells in combination with a biomaterial scaffold; articles using other dental stem cells or no scaffolds were excluded. The investigated scaffolds were organized in host-derived, naturally-derived and synthetic material categories. It was found that the biomaterial scaffolds investigated to date possess both desirable characteristics and issues that limit their clinical applications. Future research investigating the scaffolds presented in this article may, ultimately, point to a protocol for a consistent, clinically-successful regenerative endodontic therapy.

Development of anti-HER2-targeted doxorubicin-core-shell chitosan nanoparticles for the treatment of human breast cancer

Purpose: Doxorubicin (DOX) encapsulated O-succinyl chitosan graft Pluronic^® F127 (OCP) copolymer nanoparticles conjugated with an anti-HER2 monoclonal antibody were developed as targeted drug delivery vehicles for the treatment of HER2-overexpressing breast cancer.

Methods: Five percent and 10% (w/w) of O-succinyl chitosan was grafted onto Pluronic^® F127 using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) as mediated cross-linking agents. DOX was added to the copolymer solution to form DOX-nanoparticles before conjugation with anti-HER2 on the surface of the nanoparticles.

Results: DOX was encapsulated within the NP matrices at an encapsulation efficiency of 73.69 ± 0.53% to 74.65 ± 0.44% (the initial DOX concentration was 5 µg/mL). Anti-HER2 was successfully conjugated onto the surface of the nanoparticles at a moderately high conjugation efficiency of approximately 57.23 ± 0.38% to 61.20 ± 4.42%. In the in vitro DOX dissolution study, the nanoparticle formulations exhibited a biphasic drug release with an initial burst release followed by a sustained release profile at both pH 5.0 and pH 7.4. The drug was rapidly and completely released from the nanoparticles at pH 5.0. In the in vitro cytotoxicity, the anti-HER2 conjugated OCP copolymer nanoparticles showed the lowest IC₅₀, which indicated an increase in the therapeutic efficacy of DOX to treat human breast cancer cells with the HER2 overexpression.

Conclusion: Our study shows that anti-HER2 conjugated OCP copolymer nanoparticles have the potential for the development of anticancer drug carriers.

Preparation of gelatin nanoparticles by two step desolvation method for application in photodynamic therapy

Gelatin nanoparticles have recently been receiving considerable attention because they offer a good option as release systems due to their low cost, biocompatibility, biodegradability and its application in several types of formulations. This study aim was to evaluate the potential application of gelatin nanoparticles entrapping a photosensitizer in Photodynamic Therapy. Gelatin nanoparticles were studied by steady-state techniques and the biological activity evaluated by in vitro MTT assay. The particles were spherical in shape exhibiting a 273 nm diameter with a low tendency to aggregate. The loading efficiency was 76%. Photosensitizer photophysical properties were shown to be preserved after GN encapsulation. The cells viability obtaining 85% cells death compared with control. The results demonstrate that gelatin nanoparticles can be successfully applied for photosensitizers encapsulation or other active drugs and be used as an optimal medium for a variety of bioactive materials, which can also be encapsulated by the proposed method.

'In Vitro', 'In Vivo' and 'In Silico' Investigation of the Anticancer Effectiveness of Oxygen-Loaded Chitosan-Shelled Nanodroplets as Potential Drug Vector

PURPOSE

Chitosan-shelled/decafluoropentane-cored oxygen-loaded nanodroplets (OLN) are a new class of nanodevices to effectively deliver anti-cancer drugs to tumoral cells. This study investigated their antitumoral effects 'per se', using a mathematical model validated on experimental data.

METHODS

OLN were prepared and characterized either in vitro or in vivo. TUBO cells, established from a lobular carcinoma of a BALB-neuT mouse, were investigated following 48 h of incubation in the absence/presence of different concentrations of OLN. OLN internalization, cell viability, necrosis, apoptosis, cell cycle and reactive oxygen species (ROS) production were checked as described in the Method section. In vivo tumor growth was evaluated after subcutaneous transplant in BALB/c mice of TUBO cells either without treatment or after 24 h incubation with 10% v/v OLN.

RESULTS

OLN showed sizes of about 350 nm and a positive surface charge (45 mV). Dose-dependent TUBO cell death through ROS-triggered apoptosis following OLN internalization was detected. A mathematical model predicting the effects of OLN uptake was validated on both in vitro and in vivo results.

CONCLUSIONS

Due to their intrinsic toxicity OLN might be considered an adjuvant tool suitable to deliver their therapeutic cargo intracellularly and may be proposed as promising combined delivery system.

An in vitro assessment of novel chitosan/bimetallic PtAu nanocomposites as delivery vehicles for doxorubicin

AIM

To synthesize and functionalize platinum (core)-gold (shell) bimetallic nanoparticles (PtAuBNps) with chitosan and doxorubicin to display favorable pharmacokinetics, biodegradability, biological activity and safety in vitro.

MATERIALS & METHODS

PtAuBNps and their drug nanocomposites were morphologically and physico-chemically characterized. Binding studies determined the efficiency and stability of the platform. In vitro release kinetics were evaluated under simulated environments, cytotoxicity profiles through MTT and Sulforodhamine B assays and apoptosis induction using the dual EtBr/AO staining.

RESULTS & DISCUSSION

The results obtained indicate that functionalized PtAuBNps displayed favorable physio-chemical attributes, high binding capabilities, pH-triggered drug release through zero-order release kinetics, cell-specific cytotoxicity and good colloidal stability.

CONCLUSION

The positive attributes of this novel delivery system bodes well for future in vivo studies.