Browsing by Author "Chitkara, Deepak"

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2, 2-Bis (hydroxymethyl) propionic acid based cyclic carbonate monomers and their (co) polymers as advanced materials for biomedical applications
(Elsevier, 2021-08) Chitkara, Deepak; Mittal, Anupama
Designing grafted biodegradable polymers with tailored multi-functional properties is one of the most researched fields with extensive biomedical applications. Among many biodegradable polymers, polycarbonates have gained much attention due to their ease of synthesis, high drug loading, and excellent biocompatibility profiles. Among various monomers, 2,2-bis(hydroxymethyl) propionic acid (bis-MPA) derived cyclic carbonate monomers have been extensively explored in terms of their synthesis as well as their polymerization. Since the late 90s, significant advancements have been made in the design of bis-MPA derived cyclic carbonate monomers as well as in their reaction schemes. Currently, bis-MPA derived polycarbonates have taken a form of an entire platform with a multitude of applications, the latest being in the field of nanotechnology, targeted drug, and nucleic acid delivery. The present review outlines an up to date developments that have taken place in the last two decades in the design, synthesis, and biomedical applications of bis-MPA derived cyclic carbonates and their (co)polymers
Advancements in Polymeric Systems for Nucleic Acid Delivery
(CRC Press, 2018) Chitkara, Deepak; Mittal, Anupama
RNA interference (RNAi) has been suggested as a potential treatment method to improve current chemotherapeutic regimens. It is a sequence-specific, post-transcriptional gene silencing mechanism in animals and plants that targets mRNA encoded by the mutant gene. RNA-based strategies are useful in targeting the mutations that results in a gain of function wherein RNA levels are modified and includes the use of antisense oligonucleotide, triplex-forming oligonucleotides, aptamers, trans-splicing, segmental trans-splicing, ribozymes, DNAzymes, siRNA, and miRNA (Chitkara, Singh, & Mittal, 2016). Among these, siRNA and miRNA have generated a lot of interest as they could be easily synthesized, do not require genome integration, and thus could curtail potential problems of insertional mutagenesis. These are 20–25 base pair-long RNA oligonucleotides that are incorporated into the pre-RISC (RNA-induced
Asiaticoside polymeric nanoparticles for effective diabetic wound healing through increased collagen biosynthesis: In-vitro and in-vivo evaluation
(Elsevier, 2023-01) Chitkara, Deepak; Mittal, Anupama
Asiaticoside (AST) is a naturally available phytoconstituent that enables effective wound healing mainly by promoting collagen biosynthesis. However, the physicochemical nature of AST such as high molecular weight (959.12 g/mol), poor water solubility and poor permeability limits its therapeutic effects. This study aims to develop Asiaticoside polymeric nanoparticles (AST PNP) embedded in a gelatin based biodegradable hydrogel (15 % w/v) for application in the wound cavity to enable sustained release of AST and enhance its therapeutic effects. The AST PNP were fabricated in the desired size range (168.4 nm; PDI (0.09)) and the morphology, rate of fluid uptake, rate of water loss, and water vapor transmission rate of AST PNP incorporated hydrogel were determined. AST PNP gel showed porous structural morphology and possessed ideal characteristics as a graft for wound healing. The drug release kinetics and cellular uptake of AST PNP were investigated wherein, AST PNP demonstrated sustained release profile upto 24 h in comparison to free AST (complete release within 6 h) and exhibited an enhanced intra-cellular uptake in fibroblasts within 3 h compared to the free drug. In-vitro cell culture studies also demonstrated significant proliferation and migration of fibroblasts in the presence of AST PNP. Additionally, AST PNP gel upon application to the wounds of diabetic rats depicted improved wound healing efficacy in terms of improved collagen biosynthesis, upregulated COL-1 protein level (∼1.85 fold vs free AST), and enhanced expression of α-SMA compared to control groups. Altogether, formulation of AST as polymeric nanoparticles in a gel based carrier offered significant improvement in the therapeutic properties of AST for the management of diabetic wounds.
Aspartic acid tagged carbon nanotubols as a tool to deliver docetaxel to breast cancer cells: Reduced hemotoxicity with improved cytotoxicity
(Elsevier, 2019-09) Chitkara, Deepak
The present study aimed to explore the potential of hydroxylated carbon nanotubes (CNTnols) conjugated with aspartic acid for the delivery of docetaxel (DTX) to breast cancer cells. The conjugate was well-characterized by FT-IR, NMR, XRD and FE-SEM. The nanoconjugate offered a hydrodynamic diameter of 86.31 ± 1.02 nm, with a PDI of 0.113 and zeta potential of −41.6 ± 0.17 mV. The designed nanosystem offered a controlled & pH dependent release vouching release of drug in the cancerous cytosol, not in blood, assuring delivery of the pay-load to the site of action. The carriers offered substantial hemocompatibility and lower plasma protein binding, ensuring more drug available at the site of action. The in-vitro cell viability studies in MDA MB-231 cells inferred approx. 2.8 times enhancement in the cytotoxicity potential of the conjugate vis-à-vis plain drug. Pharmacokinetic studies also corroborated the superiority of the designed nanoconjugate in terms of enhanced bioavailable fractions, reduced clearance and longer bioresidence to that of plain docetaxel. The present studies, successfully provide a workable nanomedicine, loaded with a BCS class-IV drug, for improved efficacy and safety in breast cancer.
Autophagy as a potential therapeutic target in regulating improper cellular proliferation
(Frontiers Media, 2025-05) Chitkara, Deepak
Autophagy is a degradative process that makes rapid turnover of old and impaired proteins and organelles possible. It is highly instigated by stress signals, like starvation, and contributes to the cell’s homeostasis. Autophagy performs a crucial function in keeping cell genomic integrity stable. Impaired autophagic flux is implicated in neurodegenerative diseases, abnormal ageing, and cancerous diseases. In diseases like cancer, autophagy performs a dualistic function; it can have both a tumor-suppressive and supportive role. Autophagy in the initial phases of tumorigenesis maintains the integrity of the genome and, if it fails, leads to cell death, thus having a tumor-suppressive role. Meanwhile, autophagy also imparts the function of the pro-survival mechanism in the latter stages of tumorigenesis and supports the cancerous cells in surviving conditions like hypoxia and increased oxidative stress. Autophagy also helps cancerous cells develop drug resistance in some cases. Thus, modulation of the autophagic mechanism is a possible therapeutic strategy in cancer therapy as its inhibition can sensitise cancer cells to anti-cancerous drugs. The promotion of autophagy, in some cases, can also safeguard cells from toxic protein aggregation and enhanced oxidative stress. Excessive autophagy can result in autophagic cell death. Autophagy also regulates several cellular processes and cell death pathways, like apoptosis. Therefore, an in-depth knowledge of the autophagy process and its regulating molecules is critically important. Pharmaceutical small molecules or cellular target modulation can help modulate the cellular autophagy process in the context of specific disease conditions.
Belinostat loaded lipid–polymer hybrid nanoparticulate delivery system for breast cancer: improved pharmacokinetics and biodistribution in a tumor model
(RSC, 2023-10) Chitkara, Deepak; Mittal, Anupama
Despite various treatment modalities for breast cancer, it still persists as one of the most diagnosed types of cancer in females. The recent investigations in the epigenetics of breast cancer reveal several aberrations in the expression levels of various HDAC enzymes. Henceforth, the present work entails the formulation and characterization of a lipid polymer-based hybrid nanoparticulate (LPN) system for delivery of an epigenetic modulator drug, Belinostat, for its clinical application in breast cancer. The size of Belinostat nanoparticles prepared using a modified hot homogenization method was found to be 166.6 ± 19.95 nm with an encapsulation efficiency of 94.5 ± 5.1%. In vitro characterization for cytotoxicity, cellular uptake, and protein expression in two different breast cancer cells, 4T1 and MCF 7, revealed the superiority of the formulation in comparison with the free drug in MCF 7 cells. Subsequently, the behaviour of the formulation in in vivo settings of healthy and breast cancer xenograft bearing animals was analyzed using pharmacokinetic and biodistribution studies. The results revealed that the formulation demonstrated multi-fold improvement in the pharmacokinetic parameters in tumor bearing animals when compared with the free drug while no difference in pharmacokinetic behaviour was observed in healthy animals indicating the altered biodistribution and specificity of the formulation in breast tumor. This was confirmed by the biodistribution studies exhibiting 20-fold improved uptake and retention of the nanoparticulate formulation in tumor tissues of the animal model at the end of 4 h. Thus, the developed LPN system holds potential to act as a novel drug delivery system for Belinostat with several advantages over the free drug.
Bile-Acid-Appended Triazolyl Aryl Ketones: Design, Synthesis, In Vitro Anticancer Activity and Pharmacokinetics in Rats
(MDPI, 2021-09-17) Sakhuja, Rajeev; Mazumdar, Samrat; Chitkara, Deepak
A library of bile-acid-appended triazolyl aryl ketones was synthesized and characterized by detailed spectroscopic techniques such as 1H and 13C NMR, HRMS and HPLC. All the synthesized conjugates were evaluated for their cytotoxicity at 10 µM against MCF-7 (human breast adenocarcinoma) and 4T1 (mouse mammary carcinoma) cells. In vitro cytotoxicity studies on the synthesized conjugates against MCF-7 and 4T1 cells indicated one of the conjugate 6cf to be most active against both cancer cell lines, with IC50 values of 5.71 µM and 8.71 µM, respectively, as compared to the reference drug docetaxel, possessing IC50 values of 9.46 µM and 13.85 µM, respectively. Interestingly, another compound 6af (IC50 = 2.61 µM) was found to possess pronounced anticancer activity as compared to the reference drug docetaxel (IC50 = 9.46 µM) against MCF-7. In addition, the potent compounds (6cf and 6af) were found to be non-toxic to normal human embryonic kidney cell line (HEK 293), as evident from their cell viability of greater than 86%. Compound 6cf induces higher apoptosis in comparison to 6af (46.09% vs. 33.89%) in MCF-7 cells, while similar apoptotic potential was observed for 6cf and 6af in 4T1 cells. The pharmacokinetics of 6cf in Wistar rats showed an MRT of 8.47 h with a half-life of 5.63 h. Clearly, these results suggest 6cf to be a potential candidate for the development of anticancer agents
Biocompatible Phospholipid-Based Mixed Micelles for Tamoxifen Delivery: Promising Evidences from In - Vitro Anticancer Activity and Dermatokinetic Studies
(Springer, 2017) Chitkara, Deepak
Tamoxifen (TAM) is frequently prescribed for the management breast cancer, but is associated with the challenges like compromised aqueous solubility and poor bioavailability to the target site. It was envisioned to develop phospholipid-based mixed micelles to explore the promises offered by the biocompatible carriers. Various compositions were prepared, employing soya lecithin, polysorbate 80, sodium chloride/dextrose, and water, by self-assembled technique. The formulations were characterized for micromeritics and evaluated for in vitro drug release, hemolysis study, dermatokinetic studies on rodents, and cytotoxicity on MCF-7 cell lines. Cellular uptake of the system was also studied using confocal laser scanning microscopy. The selected composition was of sub-micron range (28.81 ± 2.1 nm), with spherical morphology. During in-vitro studies, the mixed micelles offered controlled drug release than that of conventional gel. Cytotoxicity was significantly enhanced and IC50 value was reduced that of the naïve drug. The bioavailability in epidermis and dermis skin layers was enhanced approx. fivefold and threefold, respectively. The developed nanosystem not only enhanced the efficacy of the drug but also maintained the integrity of skin, as revealed by histological studies. The developed TAM-nanocarrier possesses potential promises for safe and better delivery of TAM.
Biodegradable Injectable In Situ Depot-Forming Drug Delivery Systems
(Wiley, 2006-11) Chitkara, Deepak
The scope of drug-delivery systems has expanded significantly in recent years providing new ways to deliver life saving therapeutics to patients. The development of new injectable drug-delivery systems has provided new vistas and opened up unexplored horizons in the field of science, particularly in controlled drug delivery since these systems possess unique advantages over traditional ones, which include ease of application, and localized and prolonged drug delivery. In the past few years, an increasing number of such systems has been reported in the literature for various biomedical applications, including drug delivery, cell encapsulation, and tissue repair. These are injectable fluids that can be introduced into the body in a minimally invasive manner prior to solidifying or gelling within the desired site. For this purpose both natural (chitosan, alginates) as well as synthetic polymers (PEGylated polyesters, ricinoleic acid-based polymers) have been utilized. These systems have been explored widely for the delivery of various therapeutic agents ranging for anti-neoplastic agents like paclitaxel to proteins and peptides such as insulin, almost covering every segment of the pharmaceutical field. This manuscript focuses on the recent advancements in the area of in situ forming biodegradable polymeric drug-delivery systems.
BSA-PLGA-Based Core-Shell Nanoparticles as Carrier System for Water-Soluble Drugs
(Springer, 2013) Chitkara, Deepak
Preparation, optimization and in vitro evaluation of core-shell nanoparticles comprising of a hydrophilic core of BSA surrounded by a hydrophobic shell of PLGA for loading water-soluble drugs.
Can breakthroughs in dermal and transdermal macromolecule delivery surmount existing barriers and revolutionize future therapeutics?
(Springer, 2025-05) Mittal, Anupama; Chitkara, Deepak
The delivery of macromolecules through dermal and transdermal routes presents both significant challenges and transformative opportunities in therapeutic applications. This review highlights the most recent advancements and innovative strategies aimed at overcoming the barriers associated with macromolecular delivery. Cutting-edge approaches such as the use of adjuvants (e.g., hyaluronic acid-based and chemical penetration enhancers), bioactive peptides with diverse functionalities, and mechanical force techniques—including iontophoresis, microneedles, and electroporation—are thoroughly explored. While various strategies have been implemented to enhance skin delivery, they often present significant challenges, particularly for macromolecules. Addressing these challenges requires integrating novel technologies and understanding the interplay between biological barriers and delivery mechanisms. Furthermore, the role of nanotechnology, through systems like nanoemulsions, polymeric nanoparticles, and transferosomes, is examined for its ability to protect macromolecules and regulate their release. Notably, this review provides unique perspectives on the interplay between these strategies and their potential to revolutionise future therapeutics. By highlighting key trends and advancements in macromolecule delivery, this review underscores the importance of innovative approaches in overcoming existing barriers and enabling efficient drug administration.
Cationic lipopolymeric nanoplexes containing the CRISPR/Cas9 ribonucleoprotein for genome surgery
(RSC, 2022-07) Chitkara, Deepak; Mittal, Anupama
sgRNA/Cas9 ribonucleoproteins (RNPs) provide a site-specific robust gene-editing approach avoiding the mutagenesis and unwanted off-target effects. However, the high molecular weight (∼165 kDa), hydrophilicity and net supranegative charge (∼−20 mV) hinder the intracellular delivery of these RNPs. In the present study, we have prepared cationic RNPs lipopolymeric nanoplexes that showed a size of 117.3 ± 7.64 nm with +6.17 ± 1.04 mV zeta potential and >90% entrapment efficiency of RNPs. Further, these RNPs lipopolymeric nanoplexes showed good complexation efficiency and were found to be stable for 12 h with fetal bovine serum. These RNPs lipopolymeric nanoplexes did not induce any significant cytotoxicity in HEK293T cells, and were efficiently uptaken via a clathrin-mediated pathway with optimal transfection efficiency and nuclear localization after 48 h. Further, HEK293T cells having the mGFP insert were used as a cell line model for gene editing, wherein the loss of the mGFP signal was observed as a function of gene editing after transfection with mGFP targeting RNPs lipopolymeric nanoplexes. Further, the T7 endonuclease and TIDE assay data showed a decent gene editing efficiency. Additionally, the lipopolymeric nanoplexes were able to transfect muscle cells in vivo, when injected intra-muscularly. Collectively, this study explored the potential of cationic lipopolymeric nanoplexes for delivering gene-editing endonucleases.
Chemoresistance in Prostate Cancer Cells Is Regulated by miRNAs and Hedgehog Pathway
(PLOS, 2012-06) Chitkara, Deepak
Many prostate cancers relapse due to the generation of chemoresistance rendering first-line treatment drugs like paclitaxel (PTX) ineffective. The present study aims to determine the role of miRNAs and Hedgehog (Hh) pathway in chemoresistant prostate cancer and to evaluate the combination therapy using Hh inhibitor cyclopamine (CYA). Studies were conducted on PTX resistant DU145-TXR and PC3-TXR cell lines and clinical prostate tissues. Drug sensitivity and apoptosis assays showed significantly improved cytotoxicity with combination of PTX and CYA. To distinguish the presence of cancer stem cell like side populations (SP), Hoechst 33342 flow cytometry method was used. PTX resistant DU145 and PC3 cells, as well as human prostate cancer tissue possess a distinct SP fraction. Nearly 75% of the SP cells are in the G0/G1 phase compared to 62% for non-SP cells and have higher expression of stem cell markers as well. SP cell fraction was increased following PTX monotherapy and treatment with CYA or CYA plus PTX effectively reduced their numbers suggesting the effectiveness of combination therapy. SP fraction cells were allowed to differentiate and reanalyzed by Hoechst staining and gene expression analysis. Post differentiation, SP cells constitute 15.8% of total viable cells which decreases to 0.6% on treatment with CYA. The expression levels of P-gp efflux protein were also significantly decreased on treatment with PTX and CYA combination. MicroRNA profiling of DU145-TXR and PC3-TXR cells and prostate cancer tissue from the patients showed decreased expression of tumor suppressor miRNAs such as miR34a and miR200c. Treatment with PTX and CYA combination restored the expression of miR200c and 34a, confirming their role in modulating chemoresistance. We have shown that supplementing mitotic stabilizer drugs such as PTX with Hh-inhibitor CYA can reverse PTX chemoresistance and eliminate SP fraction in androgen independent, metastatic prostate cancer cell lines.
Chitosan-modified PLGA polymeric nanocarriers with better delivery potential for tamoxifen
(Elsevier, 2016-12) Chitkara, Deepak
Breast cancer is believed as the second most common cause of cancer-related deaths in women for which tamoxifen is frequently prescribed. Despite many promises, tamoxifen is associated with various challenges like low hydrophilicity, poor bioavailability and dose-dependent toxicity. Therefore, it was envisioned to develop tamoxifen- loaded chitosan-PLGA micelles for potential safe and better delivery of this promising agent. The chitosan-PLGA copolymer was synthesised and characterised by Fourier Transform-Infrared, Ultraviolet-visible and Nuclear Magnetic Resonance spectroscopic techniques. The drug-loaded nanocarrier was characterised for drug-pay load, micrometrics, surface charge and morphological attributes. The developed system was evaluated for in-vitro drug release, haemolytic profile, cellular-uptake, anticancer activity by cytotoxicity assay and dermatokinetic studies. The developed nano-system was able to substantially load the drug and control the drug release. The in-vitro cytotoxicity offered by the system was significantly enhanced vis-a-vis plain drug, and there was no substantial haemolysis. The IC50 values were significantly decreased and the nanocarriers were uptaken by MCF-7 cells, noticeably. The carrier was able to locate the drug in the interiors of rat skin in considerable amounts to that of the conventional product. This approach is promising as it provides a biocompatible and effective option for better delivery of tamoxifen.
Cholesterol and Morpholine Grafted Cationic Amphiphilic Copolymers for miRNA-34a Delivery
(ACS, 2018-05) Chitkara, Deepak; Mittal, Anupama
miR-34a is a master tumor suppressor playing a key role in the several signaling mechanisms involved in cancer. However, its delivery to the cancer cells is the bottleneck in its clinical translation. Herein we report cationic amphiphilic copolymers grafted with cholesterol (chol), N,N-dimethyldipropylenetriamine (cation chain) and 4-(2-aminoethyl)morpholine (morph) for miR-34a delivery. The copolymer interacts with miR-34a at low N/P ratios (∼2/1) to form nanoplexes of size ∼108 nm and a zeta potential ∼ +39 mV. In vitro studies in 4T1 and MCF-7 cells indicated efficient transfection efficiency. The intracellular colocalization suggested that the copolymer effectively transported the FAM labeled siRNA into the cytoplasm within 2 h and escaped from the endo-/lysosomal environment. The developed miR-34a nanoplexes inhibited the breast cancer cell growth as confirmed by MTT assay wherein 28% and 34% cancer cell viability was observed in 4T1 and MCF-7 cells, respectively. Further, miR-34a nanoplexes possess immense potential to induce apoptosis in both cell lines.
Coenzyme Q10 loaded lipid-polymer hybrid nanoparticles in gel for the treatment of psoriasis like skin condition
(Elsevier, 2022-10) Chitkara, Deepak; Mittal, Anupama
Psoriasis is characterized by severe dermal inflammation caused by pre-oxidants that dominate the skin's antioxidant system. The available therapeutic strategies seeks betterment in terms of cost effectiveness, long-term usage and safety. This research work highlights the use of monolithic polymer-lipid hybrid nanoparticles to deliver coenzyme Q10, a prominent antioxidant and anti-inflammatory biomolecule, to the skin. The system has both polymeric and lipidic characteristics, so each could compensate the other's shortcomings. The particle size, polydispersity index, and encapsulation efficiency of the nanoformulation were found to be 121 ± 11.61 nm, 0.252 ± 0.073, and 78.57 ± 3.88%, respectively, when produced employing the hot homogenization technique. The nanoparticles released CoQ10 steadily and consistently for up to 3 days. Further, the nanoformulation was used as a topical gel (CoQ10–0.06% w/w), and demonstrating non-newtonian rheological characteristics. An imiquimod-induced psoriatic mouse model was used to evaluate the in vivo efficacy of the nanoformulation gel, which produced a significant increase in CoQ10 efficacy when applied topically compared to free CoQ10 gels. Overall, the CoQ10 loaded NanoHybrid gel was found to be efficient for the in vivo application for the treatment of psoriasis like skin conditions.
Core-shell nanoparticulate formulation of gemcitabine: lyophilization, stability studies, and in vivo evaluation
(Springer, 2014-10) Chitkara, Deepak; Mittal, Anupama
Core-shell nanoparticulate formulation of gemcitabine was prepared by incorporating gemcitabine in a hydrophilic bovine serum albumin (BSA) core surrounded by hydrophobic poly(dl-lactic acid-co-glycolic acid) (PLGA) shell with a particle size of 243 nm and encapsulation efficiency of 40.5 %. Prepared formulations were lyophilized, wherein several cryoprotectants were screened for product attributes such as cake appearance, reconstitution with water, and size constancy. Trehalose was screened as a lyoprotectant, which showed stability for 6 months at 5 °C and 25 °C/60 % relative humidity (RH) conditions. However, an increase in particle size was observed at accelerated conditions (40 °C/75 % RH). In vitro evaluation of these nano-formulations in MCF-7 breast cancer cells showed enhanced cellular uptake (90 %) as compared to GEMCITE® uptake (51 %) in 6 h along with reduced IC50 value at 72 h (16 μM versus 30 μM). In vivo studies in Sprague Dawley rats showed C max, t 1/2, and area under the curve (AUC) at 2.55 μg/ml, 13.6 h, and 28,322.5 μg/l/h, respectively, whereas GEMCITE® at the same dose showed significantly lower corresponding values at 1.94 μg/ml, 6.89 h, and 13,967 μg/l/h. In the same study, AUC and C max of inactive metabolite of gemcitabine (dFdU) were reduced by 33 and 42 %, respectively, for these nanoparticles compared to GEMCITE®. In 7,12-dimethylbenz[a]anthracene (DMBA)-induced breast cancer model, significantly reduced tumor growth was observed in gemcitabine-loaded-nanoparticle-treated animals compared with GEMCITE®-treated animal at equivalent dose (121 versus 243 % in 30 days). The results indicated that our core-shell nanoparticles are more effective for tumor reduction compared to marketed formulation of gemcitabine, GEMCITE®.
cRGD-functionalized nanohybrid conjugates codelivering temozolomide and rapamycin for treating Glioblastoma multiforme: in vitro and in vivo evaluation
(ACS, 2025-10) Mittal, Anupama; Chitkara, Deepak
The conventional treatment of glioblastoma multiforme primarily uses Temozolomide as a chemoadjuvant alongside debulking surgery and radiotherapy; however, resistance, as well as tumor recurrence, remains a common outcome. Employing combination therapy to target multiple pathways while improving delivery with advanced systems has always been sought after. Herein, we report cRGD-functionalized hybrid polymeric nanoconjugates that could deliver Temozolomide (TMZ) and rapamycin (RAP) (cRGD-Hybrid TMZ/R NCs) as a dual payload. The cRGD-Hybrid TMZ/R NCs were thoroughly characterized, exhibiting a particle size and surface zeta potential of 141.83 nm (PDI 0.233) and −0.168 mV, respectively. The nanoconjugates carrying TMZ and RAP as dual payloads were initially screened for synergism by determining their combination index in C6 and U87MG glioma cells. Further, in vitro cell-based assays showed improved cellular uptake, cytotoxicity, and apoptotic potential of hybrid nanoconjugates. Thereafter, the cRGD-Hybrid TMZ/R NCs were evaluated in a C6-cell-induced syngeneic orthotropic glioma model in Sprague–Dawley rats, exhibiting an improved therapeutic outcome including, reduced hemispherical width (RH/LH) ratios, tumor burden, and improved survival rates compared to the free drug(s) counterpart. The histopathological evaluation indicated no major sign of toxicity in vital organs such as heart, lungs, liver, kidney, and spleen, affirming the biocompatibility of the developed cRGD-Hybrid TMZ/R nanoconjugates. In conclusion, amalgamating the cRGD cell-penetrating peptide with polymer hybrid nanoconjugates presents a better approach for delivering multiple payloads in the treatment of GBM.
cRGD-modified hybrid lipopolymeric nanoplexes for gene editing in the posterior segment of the eye
(Elsevier, 2024-06) Chitkara, Deepak
Eye-related diseases, specifically retinal dystrophy (RD) conditions, are the leading cause of blindness worldwide. Gene addition, regulation, or editing could potentially treat such diseases through gene expression regulation. CRISPR/Cas9 gene editing is one of the most prominent and precise gene editing tools which could be employed to edit genes related to the dystrophic condition. However, CRISPR/Cas9 faces in vivo delivery challenges due to its high molecular weight, negative charge, prone to degradation in the presence of nucleases and proteases, poor cellular degradation, etc., which makes it challenging to adopt for therapeutic applications. We developed cRGD-modified lipopolymeric nanoplexes loaded with Cas9 RNPs with a particle size and zeta potential of 175 ± 20 nm and 2.15 ± 0.9 mV, respectively. The cRGD-modified lipopolymeric nanoplexes were stable for 194 h and able to transfect >70 % ARPE-19 and NIH3T3 cells with an Indel frequency of ~40 % for the VEGF-A gene. The cRGD-modified lipopolymeric nanoplexes found good vitreous mobility and could transfection retinal cells in vivo after 48 h of intravitreal injection in Wistar Rats. Moreover, in vivo VEGFA gene editing was ~10 % with minimal toxicities. Collectively, the cRGD-modified lipopolymeric nanoplexes were found to have extreme potential in delivering CRISPR/Cas9 RNPs payload to the retinal tissues for therapeutic applications.
CRISPR/Cas mediated epigenome editing for cancer therapy
(Elsevier, 2022-08) Chitkara, Deepak
The understanding of the relationship between epigenetic alterations, their effects on gene expression and the knowledge that these epigenetic alterations are reversible, have opened up new therapeutic pathways for treating various diseases, including cancer. This has led the research for a better understanding of the mechanism and pathways of carcinogenesis and provided the opportunity to develop the therapeutic approaches by targeting such pathways. Epi-drugs, DNA methyl transferase (DNMT) inhibitors and histone deacetylase (HDAC) inhibitors are the best examples of epigenetic therapies with clinical applicability. Moreover, precise genome editing technologies such as CRISPR/Cas has proven their efficacy in epigenome editing, including the alteration of epigenetic markers, such as DNA methylation or histone modification. The main disadvantage with DNA gene editing technologies is off-target DNA sequence alteration, which is not an issue with epigenetic editing. It is known that cancer is linked with epigenetic alteration, and thus CRISPR/Cas system shows potential for cancer therapy via epigenome editing. This review outlines the epigenetic therapeutic approach for cancer therapy using CRISPR/Cas, from the basic understanding of cancer epigenetics to potential applications of CRISPR/Cas in treating cancer.