Department of Pharmacy
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Item cRGD-functionalized nanohybrid conjugates codelivering temozolomide and rapamycin for treating Glioblastoma multiforme: in vitro and in vivo evaluation(ACS, 2025-10) Mittal, Anupama; Chitkara, DeepakThe 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.Item Temozolomide-fatty acid conjugates for glioblastoma multiforme: In vitro and in vivo evaluation(Elsevier, 2023-07) Chitkara, Deepak; Mittal, AnupamaGlioblastoma multiforme (GBM) is the deadliest brain tumor with a poor prognosis and limited therapeutic options. Temozolomide (TMZ) is the first-line chemotherapeutic agent used for the treatment of GBM; however, it suffers from several limitations, including short half-life, rapid metabolism, <1% brain bioavailability, methyl guanine methyl transferase (MGMT) based chemoresistance, and hematological toxicities. Several approaches have been adopted to overcome these limitations, particularly by using nanotechnology-based systems, but its physicochemical properties make TMZ challenging to load into these nanocarriers. In the current research, we conjugated TMZ with different fatty acids, i.e., linoleic acid (LA), oleic acid (OA), and palmitic acid (PA), to obtain TMZ-fatty acid conjugates, which are comparatively hydrophobic, less prone to degradation and potent. These conjugates were thoroughly characterized using 1H NMR spectroscopy, high-resolution mass spectrometry (HR-MS), and reverse phase-high performance liquid chromatography (RP-HPLC). The synthesized conjugates, namely Temozolomide-oleic acid (TOA,6R1), Temozolomide-linoleic acid (TLA, 6R2), and Temozolomide-palmitic acid (TPA, 6R3), showed an IC50 of 101.4, 67.97, and 672.04 μM, respectively in C6 cells and 428.257, 366.43 and 413.69 μM, respectively in U87-MG cells. On the other hand, the free TMZ showed an IC50 of >1000 μM and 564.23 μM in C6 and U87-MG, respectively. Further, the in vivo efficacy of the TMZ-fatty acid conjugates was evaluated in the C6-induced orthotropic rat glioblastoma model, wherein the TMZ-fatty acid conjugate showed improved survival rate (1.6 folds) and overall health of the animals. Collectively, the conjugation of fatty acids with TMZ improves its anticancer potential against glioblastoma multiforme (GBM).Item Polymeric and small molecule-conjugates of temozolomide as improved therapeutic agents for glioblastoma multiforme(Elsevier, 2022-10) Chitkara, Deepak; Mittal, AnupamaTemozolomide (TMZ), an imidazotetrazine, is a second-generation DNA alkylating agent used as a first-line treatment of glioblastoma multiforme (GBM). It was approved by FDA in 2005 and declared a blockbuster drug in 2008. Although TMZ has shown 100% oral bioavailability and crosses the blood-brain barrier effectively, however it suffers from limitations such as a short half-life (∼1.8 h), rapid metabolism, and lesser accumulation in the brain (∼10–20%). Additionally, development of chemoresistance has been associated with its use. Since it is a potential chemotherapeutic agent with an unmet medical need, advanced delivery strategies have been explored to overcome the associated limitations of TMZ. Nanocarriers including liposomes, solid lipid nanoparticles (SLNs), nanostructure lipid carriers (NLCs), and polymeric nanoparticles have demonstrated their ability to improve its circulation timeItem New strategies for cancer management: how can temozolomide carrier modifications improve its delivery?(Future Science Group, 2017-06) Chitkara, Deepak; Mittal, AnupamaGlioblastoma multiform (GBM) is the most devastating, highly aggressive astrocytic cell neoplasm having a median survival of 12–15 months and a 5-year survival rate of <3% [1]. Surgery along with radiation therapy and/or chemotherapy is the standard treatment strategy for primary brain tumors wherein, the survival advantages are only palliative. Despite clinical and technological advances, a cure for GBM remains elusive due to its diffuse infiltrative pattern of growth (hindering complete surgical resection), cytogenetic heterogeneity (limiting the use of pathway-specific targeted agents) and location (need to cross the blood–brain barrier [BBB]). Temozolomide (TMZ) is the first-line chemotherapy for GBM used in conjunction with radiotherapy or as a single agent for maintenance therapy [1]. It is an imidazotetrazine class DNA alkylating agent that methylates guanine and adenine bases of DNA leading to DNA double-strand breaks, cell cycle arrest and eventual cell death [1]. An autophagy induction leading to cell death has also been reported as a putative mechanism of action of TMZ in cancer cells and GBM patients [2]. Looking at the current therapy for GBM, there is still an unmet medical need resulting due to its inefficient delivery of TMZ to the cancer tissue. Only a modest activity is seen for TMZ, particularly in high-grade gliomas, which is further limited by the development of resistance leaving no viable therapeutic option for recurrent glioblastoma [3]. Further, TMZ is an unstable molecule that undergoes rapid hydrolysis and has significant dose-limiting hematological toxicity that prevents dosage increase [1]. Currently, TMZ is given orally or intravenously (TEMODAR®) at a dose of 75 mg/m2 concomitant with radiotherapy for 49 days followed by 150 mg/m2 (cycle 1) and 200 mg/m2 (cycle 2–6) as a maintenance dose.Item RNA Interference Nanotherapeutics for Treatment of Glioblastoma Multiforme(ACS, 2020-09) Chitkara, Deepak; Mittal, AnupamaNucleic acid therapeutics for RNA interference (RNAi) are gaining attention in the treatment and management of several kinds of the so-called “undruggable” tumors via targeting specific molecular pathways or oncogenes. Synthetic ribonucleic acid (RNAs) oligonucleotides like siRNA, miRNA, shRNA, and lncRNA have shown potential as novel therapeutics. However, the delivery of such oligonucleotides is significantly hampered by their physiochemical (such as hydrophilicity, negative charge, and instability) and biopharmaceutical features (in vivo serum stability, fast renal clearance, interaction with extracellular proteins, and hindrance in cellular internalization) that markedly reduce their biological activity. Recently, several nanocarriers have evolved as suitable non-viral vectors for oligonucleotide delivery, which are known to either complex or conjugate with these oligonucleotides efficiently and also overcome the extracellular and intracellular barriers, thereby allowing access to the tumoral micro-environment for the better and desired outcome in glioblastoma multiforme (GBM). This Review focuses on the up-to-date advancements in the field of RNAi nanotherapeutics utilized for GBM treatment.