Increased Levels of Autoantibodies against ROS-Modified Proteins in Depressed Individuals with Decrease in Antibodies against SARS-CoV-2 Antigen (S1-RBD).

Coronavirus 2019 (COVID-19) disease management is highly dependent on the immune status of the infected individual. An increase in the incidence of depression has been observed during the ongoing COVID-19 pandemic. Autoantibodies against in vitro reactive oxygen species (ROS) modified BSA and Lys as well as antibodies against receptor binding domain subunit S1 (S1-RBD) (S1-RBD-Abs) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were estimated using direct binding and competition ELISA. Serum samples were also tested for fasting blood glucose (FBG), malondialdehyde (MDA), carbonyl content (CC), interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α). Significant structural changes were observed in ROS modified BSA and Lys. Female depressed subjects who were also smokers (F-D-S) showed the highest levels of oxidative stress (MDA and CC levels). Similarly, increased levels of autoantibodies against ROS modified proteins were detected in F-D-S subjects, in males who were depressed and in smokers (M-D-S) compared to the other subjects from the rest of the groups. However, contrary to this observation, levels of S1-RBD-Abs were found to be lowest in the F-D-S and M-D-S groups. During the pandemic, large numbers of individuals have experienced depression, which may induce excessive oxidative stress, causing modifications in circulatory proteins. Thus, the formation of neo-antigens is induced, which lead to the generation of autoantibodies. The concomitant effect of increased autoantibodies with elevated levels of IFN-γ and TNF-α possibly tilt the immune balance toward autoantibody generation rather than the formation of S1-RBD-Abs. Thus, it is important to identify individuals who are at risk of depression to determine immune status and facilitate the better management of COVID-19.

Haemophilic arthropathy of the knee: a surgeon's nightmare.

Surgical management of knee synovitis secondary to mild haemophilia, without any significant previous medical history and an adverse family history of haematological disorders, is arduous. Due to its rare occurrence, the diagnosis is often delayed or sometimes missed, leading to the grave and often lethal consequences in intraoperative and postoperative periods. Hardly isolated knee arthropathy due to mild haemophilia has been reported in the available literature. In this report, we present the management of a case of a 16-year-old male with isolated knee synovitis with undiagnosed mild haemophilia, who came to us with the first episode of knee bleeding. We elucidate the signs and symptoms, investigations, surgical management, and difficulties faced, especially during the postoperative period. This case report is presented to enhance awareness of the existence of this disorder and its management to prevent postoperative complications.

Effectiveness of Ponseti technique in management of arthrogrypotic clubfeet - a prospective study.

BACKGROUND: Clubfoot constitutes roughly 70 percent of all foot deformities in arthrogryposis syndrome and 98% of those in classic arthrogryposis. Treatment of arthrogrypotic clubfoot is difficult and challenging due to a combination of factors like stiffness of ankle-foot complex, severe deformities and resistance to conventional treatment, frequent relapses and the challenge is further compounded by presence of associated hip and knee contractures. METHOD: A prospective clinical study was conducted using a sample of nineteen clubfeet in twelve arthrogrypotic children. During weekly visits Pirani and Dimeglio scores were assigned to each foot followed by manipulation and serial cast application according to the classical Ponseti technique. Mean initial Pirani score and Dimeglio score were 5.23 ± 0.5 and 15.79 ± 2.4 respectively. Mean Pirani and Dimeglio score at last follow up were 2.37 ± 1.9 and 8.26 ± 4.93 respectively. An average of 11.3 casts was required to achieve correction. Tendoachilles tenotomy was required in all 19 AMC clubfeet. RESULT: The primary outcome measure was to evaluate the role of Ponseti technique in management of arthrogrypotic clubfeet. The secondary outcome measure was to study the possible causes of relapses and complications with additional procedures required to manage clubfeet in AMC an initial correction was achieved in 13 out of 19 arthrogrypotic clubfeet (68.4%). Relapse occurred in 8 out of 19 clubfeet. Five of those relapsed feet were corrected by re-casting ± tenotomy. 52.6% of arthrogrypotic clubfeet were successfully treated by the Ponseti technique in our study. Three patients failed to respond to Ponseti technique required some form of soft tissue surgery. CONCLUSION: Based on our results, we recommend the Ponseti technique as the first line initial treatment for arthrogrypotic clubfeet. Although such feet require a higher number of plaster casts with a higher rate of tendo-achilles tenotomy but the eventual outcome is satisfactory. Although, relapses are higher than classical idiopathic clubfeet, most of them respond to re-manipulation and serial casting ± re-tenotomy.

Buttress Plate Assisted Fixation for Bicondylar Hoffa Fracture: A Missed Fracture-case Report with Review of Literature.

Introduction: Bicondylar Hoffa fractures are extremely uncommon injuries and there have only been a very small number of cases documented in the literature. Case Report: A 28-year-old male presented to emergency department with injury to right knee and leg. X-ray was taken; however, they were not sufficient to determine the precise fracture pattern, so computed tomography scan was done for establishing diagnosis. Fracture managed successfully using compression screws and buttress plate with satisfactory result after a follow-up period of 1 year with ROM 20-120° with no signs of Avascular necrosis or arthritis and we also discussed the appropriate treatment options with supporting literatures. Conclusion: We conclude by describing a rare case of Bicondylar Hoffa fracture managed by open reduction and internal fixation with cancellous screws and Buttress plating. All cases of unicondylar Hoffa must be evaluated with a high index of suspicion to not miss the cases of Bicondylar Hoffa, which is extremely uncommon injury.

Seroprevalence of Anti-S1-RBD Antibodies in Pre-pandemic and Pandemic Subjects From Hail Region, KSA.

Background: Two years into the pandemic, yet the threat of new SARS-CoV-2 variants continues to loom large. Sustained efforts are required to fully understand the infection in asymptomatic individuals and those with complications. Identification, containment, care, and preventative strategies rely on understanding the varied humoral immune responses. Methods: An in-house ELISA was developed and standardized to screen for serum IgG antibodies against the SARS-CoV-2 S1-RBD protein as an antigen. This study aims to investigate the seroprevalence of serum antibodies against S1-RBD antigen in pre-pandemic (n = 120) and during the early pandemic period (n = 120) in subjects from the Hail region, KSA and to correlate it with clinical and demographic factors. Results: Samples collected from both male (n = 60) and female (n = 60) subjects during the pandemic in the age groups of 20-40 (0.31 ± 0.029 and 0.29 ± 0.024, respectively) and 41-60 years (0.35 ± 0.026 and 0.30 ± 0.025, respectively) showed significantly higher levels of serum antibodies against S-RBD antigen than the age-matched pre-pandemic samples [male (n = 60) and female (n = 60)]. Pandemic subjects exhibited significantly (p < 0.01) higher inhibition (80-88%) than age-matched pre-pandemic subjects (32-39%). Antibodies against S1-RBD antigen were detected in approximately 10% of the total pre-pandemic population (males and females). However, subjects > 60 years did not show antibodies. Conclusion: Antibody levels increased in samples collected during the pandemic, even though these subjects were not clinically COVID-19 positive. A small number of pre-pandemic subjects showed serum antibodies, suggesting prior exposure to other coronaviruses in the region. With dwindling neutralizing antibody levels and reduced vaccine efficacy against newer variants, it remains crucial to develop better assays for surveillance, management, and future research.

Inter-dependency between surface morphology and sensitive low RH detection: exploration of an intricate mechanism to extend the lower detection limit.

The water vapor molecular dynamics inside a pore structure control both molecular adsorption and desorption processes and the limit of minimum detection (LOD). Pore morphology design, and a higher concentration of electrolyte-driven anions, in accordance with the kinetics of water vapor molecules, is reported here, as the ultimate answer to extremely low relative humidity (RH) detection. In this report, a series of samples were prepared by anodization in different voltage windows, related to specific electrolyte solutions. The sensing attributes comprised: (i) a LOD of ∼3 RH%, (ii) excellent response time (6 s) and recovery time (54 s), and (iii) a hysteresis loss of ∼0.36%, with sustained stability over the period of one year; all these occurring in a sample with a pore diameter ∼5 nm ±3 nm. Interestingly, the LOD extend towards a lower RH% with a decrease in pore diameter; and a suitable explanation is given for the entire range of humidity level, in terms of the molecular mean free path, loss of kinetic energy due to scattering inside the pores, and subsequent overall loss of Brownian energy of the molecules. It is inferred from the sensing response characteristics that pore morphology and lower detection limit are interrelated; therefore, a further extension in LOD from extremely low RH% to trace levels, needs careful engineering of the pore morphology and parameters related to molecular kinetics.

New Concept in Humidity Sensing: Role of Molecular Brownian Energy and Probabilistic Mean Free Path to differentiate RH- and Trace Level Detection.

A break in the traditional pore morphology approach in anodic alumina is presented here to see its niche merit over the conventional sensors for water vapor detection. The cylindrical pore structure was replaced with a normal cone for trace-level and inverse cone for RH-level detection. The normal conical pore was fabricated by sheer manipulation of the reaction rates of electrolytes, anodic polarization, rate and time; the procedure was reversed in the case of the inverse cone structure. A sensor with a normal cone geometry exhibits excellent response at the ppm level and slightly extended to low RH level with a detection range of 120 ppm-30% RH, having response and recovery times of 6 and 255 s, measured at 120 ppm. Lowering of the minimum detection limit further requires alteration of the conical geometric parameters, in tandem with the molecular dynamics of water vapor molecules within the pore. In contrast, a sensor developed from an inverse conical structure shows response only at the RH level, from 20% RH to 90% RH with response and recovery times of less than 60 s over the entire range. Limitations such as nonlinear response, large response-recovery time, and high hysteresis as observed in conventional anodic alumina-based humidity sensors have been removed. The sensor response in conical and inverse conical pore morphologies is compared with that of standard sensors having a cylindrical pore morphology, with a top pore diameter identical with that of the reported sensors. The standard sensors were found to detect in the RH range only, with response and recovery times below 20s. The sensing mechanisms in both structures have been suitably demonstrated and ratified with experimental data. Trace level detection is interpreted with the statistical probabilistic approach in the light of the kinetic theory of gases and Brownian energy. A correlation between top surface pore diameter (through which water molecules enter) and the optimized mean free path of vapor molecule is established, and its effectiveness has been demonstrated for humidity detection at a trace level. The results are encouraging, and the same concept may be tried for the detection of other gaseous stimuli, including organic vapors.

Development and characterization of hyaluronic acid modified PLGA based nanoparticles for improved efficacy of cisplatin in solid tumor.

Cisplatin is a potent and widely used chemotherapeutic agent to treat a variety of tumors. However, its clinical use is associated with undesirable side effects and acquired resistance to cisplatin. In this study, cisplatin loaded hyaluronic acid (HA) functionalized poly (lactic-co-glycolic acid)-poly (ethylene glycol) nanoparticles (CP-HA-PLGA-PEG-NPs) were fabricated using double emulsion solvent evaporation method to target CD44 receptor expressed on cancerous cells. The developed nanoconstructs were characterized for various in vitro parameters, including size distribution, zeta potential, morphology, drug loading and in vitro release. The HA content on the HA-PLGA-PEG-NPs was quantified by a turbidimetric method. The in vitro anticancer study in human ovarian cancer (SKOV-3) cells showed significantly (p<0.05) higher cytotoxicity of CP-HA-PLGA-PEG NPs as compared to free cisplatin and non-targeted nanoparticles (CP-PLGA-PEG NPs). Further, laser scanning confocal microscopy revealed that there was enhanced cellular uptake of HA-PLGA-PEG NPs in CD44-over expressing ovarian cancer cell line (SKOV-3). The in vivo antitumor activity of CP-HA-PLGA-PEG-NPs was significantly (p<0.05) higher than free cisplatin and CP-PLGA-PEG-NPs in Ehrlich tumor (solid) bearing mice. The results demonstrated the potential of target specific nanoconstruct of cisplatin in the improved cancer chemotherapy.

Improved efficacy of cisplatin in combination with a nano-formulation of pentacyclic triterpenediol.

Cisplatin is widely used for the treatment of various cancers including cervical, ovarian, lung and head and neck, however, its clinical success is limited owing to the dose-dependent adverse effects, mainly nephrotoxicity and neurotoxicity. In order to address this limitation, the present study was undertaken to investigate growth inhibitory effect of cisplatin in combination with a triterpenediol (3a, 24-dihydroxyurs-12-ene and 3a, 24-dihydroxyolean-12-ene, TPD) on human ovarian cancer cell line. Poly(dl-lactic-co-glycolic) acid nanoparticles loaded with TPD (TPD-PLGA-NPs) were successfully developed by emulsion solvent evaporation method. The TPD-PLGA-NPs were characterized for size distribution and zeta potential which was in order of 152.56±3.01nm and -17.36±0.37mV respectively. The morphological evaluation was carried out by transmission electron microscopy and the formulation was also characterized using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The drug loading of the optimized formulation was 51.03±1.52µg/mg and the formulation exhibited sustained drug release profile. The in vitro cellular uptake study of coumarin-6 loaded PLGA nanoparticles in OVCAR-5 cells demonstrated a time dependent increase in uptake efficiency. Further, growth inhibitory effect of cisplatin was investigated in combination with TPD-PLGA-NPs. The combination index (CI) was <1, indicating a synergistic interaction. Further, at 75% of cell growth inhibition (ED75) the dose of cisplatin was reduced to 3.8 folds using this combination. The results indicated the potential of cisplatin and TPD-PLGA-NPs combination in order to reduce to dose limiting toxicities of the former.

Long-circulatory nanoparticles for gemcitabine delivery: Development and investigation of pharmacokinetics and in-vivo anticancer efficacy.

The anticancer potential of gemcitabine, a nucleoside analog, is compromised due to the enzymatic degradation into inactive form leading to the short half-life in systemic circulation. Novel delivery strategies are required to improve therapeutic efficacy of this potential drug. Monomethoxy polyethylene glycol amine-polylactide-co-glycolide (mPEG-PLGA) co-polymer was synthesized and characterized by FTIR and (1)H NMR. Gemcitabine loaded mPEG-PLGA nanoparticles (NPs) were developed and investigated for pharmacokinetic profile and in vivo anticancer activity. The mPEG-PLGA NPs (size: 267±10nm, zeta potential: -17.5±0.2mV) exhibited sustained drug release profile and were found to be compatible with blood. The mPEG-PLGA NPs were able to evade the uptake by macrophages (i.e. THP-1 and J774A) by reducing the adsorption of proteins on the surface of NPs. The enhanced cellular uptake and cell cytotoxicity was observed by mPEG-PLGA NPs in MiaPaCa-2 and MCF-7 cells. The half-life of gemcitabine in mPEG-PLGA NPs was remarkably enhanced (19 folds) than native gemcitabine. Further, the pharmacokinetic modulation of gemcitabine using mPEG-PLGA-NPs was translated in improved anticancer efficacy as compared to native gemcitabine in Ehrlich ascites bearing Balb-c mice. The results demonstrated the potential of long-circulatory nanoparticles in improving the pharmacokinetic profile and in-turn the anticancer efficacy of gemcitabine.

Reduced toxicological manifestations of cisplatin following encapsulation in folate grafted albumin nanoparticles.

AIMS: Cisplatin is one of the most potent chemotherapeutic agents acting against a variety of tumors, however, its use is mainly limited due to the dose limiting toxicities and acquired resistance to cisplatin. Folate functionalized albumin nanoparticles were developed for targeted delivery of drug to limit the adverse effects of cisplatin. MAIN METHODS: Cisplatin loaded nanoparticles functionalized with folate (CP-FA-BSA-NPs) were developed and characterized for various parameters. In order to investigate the targeting ability of folate conjugated nanoparticles, in vitro cellular uptake study was performed in folate receptor over expressing cells (MCF-7). Further, blood urea nitrogen (BUN) level, plasma creatinine level, body weight and kidney weight of the mice were measured followed by histopathological examination of various tissues to have an insight into the potential of developed formulation in the reduction of drug associated adverse effects. KEY FINDINGS: The cellular uptake studies demonstrated higher internalization of folate conjugated nanoparticles as compared to plain counterpart (CP-BSA-NPs). Following two cycles of cisplatin treatment, a week apart, BUN and plasma creatinine level were found to be significantly higher in case of free cisplatin as compared to saline, CP-BSA-NPs and CP-FA-BSA-NPs treated groups. Body weight and kidney weight of free cisplatin treated mice were significantly reduced as compared to other group. Histopathological examination of kidney from CP-BSA-NPs and CP-FA-BSA-NPs treated groups revealed no kidney damage, however, a sign of nephrotoxicity was observed in the case of free cisplatin. SIGNIFICANCE: The results demonstrated the potential of developed formulation in reducing the adverse effects of cisplatin.

Development and evaluation of folate functionalized albumin nanoparticles for targeted delivery of gemcitabine.

Gemcitabine is one of the most potent anticancer agents acting on a wide range of solid tumors, however, its use is limited by short half life and high dose leading to serious side effects. The present investigation describes the development and characterization of folate functionalized gemcitabine loaded bovine serum albumin nanoparticles (Fa-Gem-BSANPs). The nanoparticles were prepared by desolvation cross-linking technique and characterized for various parameters including morphology, particle size, zeta potential, drug loading and release profile. The particle size of Gem-BSANPs and Fa-Gem-BSANPs was found to be 159.1±5.29 and 208.7±1.80 nm, respectively. DSC and XRD analysis indicated amorphous nature of the drug within the particles. The encapsulated gemcitabine exhibited less hemolytic properties as compared to native drug. The anticancer activity of Fa-Gem-BSANPs was evaluated in folate receptor over expressing cell lines (Ovcar-5 and MCF-7) and folate receptor deficient cell line (MIAPaCa-2). The Fa-Gem-BSANPs showed superior anticancer activity as compared to Gem-BSANPs in Ovcar-5 and MCF-7 cells while no significant difference in cytotoxicity was found with MIAPaCa-2 cells. Confocal microscopy indicated facilitated intracellular uptake of Fa-Gem-BSANPs in MCF-7, which in turn result in a higher potential for apoptosis. Further, Fa-Gem-BSANPs exhibited improved anti-tumor activity in Ehrlich solid tumor model in mice. In conclusion, our study indicates that folate functionalized nanoparticles confer enhance cellular uptake and cytotoxicity for gemcitabine.

Advances in P-glycoprotein-based approaches for delivering anticancer drugs: pharmacokinetic perspective and clinical relevance.

INTRODUCTION: P-glycoprotein (P-gp) is a multi-specific efflux transporter belonging to ATP-binding cassette (ABC) transporter family, encoded by the ABCB1 gene, which significantly impacts the pharmacokinetics as well as multidrug resistance of anticancer drugs. AREAS COVERED: This review explores how human P-gp transporters modulate the pharmacokinetics of anticancer drugs and emerging strategies to modulate their function. The key findings in direct modulation by various P-gp inhibitors on pharmacokinetics of various anticancer P-gp substrates are described. The role of pharmaceutical excipients as P-gp inhibitor with the focus on the recent development in novel drug delivery systems to modulate pharmacokinetics of anticancer drugs is also outlined. EXPERT OPINION: The concomitant use of anticancer P-gp substrate and P-gp inhibitor is an effective and safe way to enhance the bioavailability of anticancer drugs. The poor bioavailability and toxicity of anticancer drugs limit their therapeutic efficacy. These characteristics can be improved by using various nanocarriers which exhibited a high potential to bypass this efflux protein. The best combination of P-gp inhibitor and substrate anticancer drug in a single nanocarrier formulation is a future challenge and is still probably some years away from the marketplace.

Co-formulation of P-glycoprotein Substrate and Inhibitor in Nanocarriers: An Emerging Strategy for Cancer Chemotherapy.

Scientific community is striving to understand the role of P-glycoprotein (P-gp) in drug discovery programs due to its impact on pharmacokinetic and multi-drug resistance (MDR) of anticancer drugs. A number of efforts to resolve the crystal structure and understanding the mechanism of P-gp mediated efflux have been made. Several generations of Pgp inhibitors have been developed to tackle this multi-specific efflux protein. Unfortunately, these inhibitors lack selectivity, exhibit poor solubility and severe pharmacokinetic interactions restricting their clinical use. The nanocarrier drug delivery systems (NDDS) are receiving increasing attention for P-gp modulating activity of pharmaceutical excipients which are used in their fabrication. In addition, NDDS can enhance the solubility and exhibited ability to bypass P-gp mediated efflux. The co-formulation of P-gp inhibitors and substrate anticancer drugs in single drug delivery system offers the advantage of bypassing P-gp mediated drug efflux as well as inhibiting the P-gp. Moreover, severe pharmacokinetic interactions between P-gp inhibitor and substrate anticancer drugs could be avoided by using this strategy. In this article we describe the co-formulation strategies using nanocarriers for modulation of pharmacokinetics as well as multi-drug resistance of anticancer drugs along with the challenges in this area.

Paclitaxel formulations: challenges and novel delivery options.

Paclitaxel (PTX), a taxane plant product, is one of the most effective broad-spectrum anti-cancer agents and approved for the treatment of a variety of cancers including ovarian, breast, lung, head and neck as well as Kaposi's sarcoma. Poor aqueous solubility and serious side effects associated with commercial preparation of PTX (Taxol®) triggered the development of alternative PTX formulations. Over past three decades, plethora of research work has been published towards the development of cremophor free and efficient formulations. Various nanocarrier systems including nanoparticles, liposomes, micelles, bioconjugates and dendrimers have been employed in order to improve PTX solubility and eliminate undesired side effects. These nanocarriers offer the advantage of high degree of encapsulation and cellular uptake, escape from elimination by P-glycoprotein (P-gp) mediated efflux, and can be explored for targeted drug delivery. The potential of these nanocarriers is reflected by the fact that various nanocarriers of PTX are in different stages of clinical trials and a few have already been commercialized including Abraxane®, Lipusu and Genexol PM®. This review focuses on the various challenges associated with PTX formulation development, limitations of existing formulations and novel approaches for the development of alternative formulations for PTX and also highlights the development of novel formulations in clinical settings.

Targeted drug delivery systems for pancreatic cancer.

Pancreatic cancer is usually diagnosed at the advanced stages, responds poorly to the available chemotherapeutics and constitutes the major factor for high mortality rate. Selective delivery of therapeutics to their cellular targets, without side effects is the foremost objective of the current investigations for effective treatment of pancreatic cancer. The development of the drugs which can selectively target pancreatic cancer along with carriers that can deliver drugs specifically to the rapidly dividing cells is considered as magic bullet for the efficient treatment of this fatal disease. This review describes various factors hampering the efficacy of drug targeting to pancreatic cancer including stromal fortress, hypocascularity, hyaluronan and interstitial fluid pressure, and exploration of various cellular targets for the site specific drug delivery. An account of burgeoning applications of novel drug delivery systems including nanoparticles, liposomes, quantum dots, micelles and drug conjugates in the management of pancreatic cancer is also provided. Additionally, potential of target based therapeutic agents and nanomedicines in clinical trials for the pancreatic cancer therapy are highlighted.

Biodegradable polymeric system for cisplatin delivery: development, in vitro characterization and investigation of toxicity profile.

Cisplatin is one of the most potent anticancer agent used in the treatment of various solid tumors, however, its clinical use is limited due to severe adverse effects including nephrotoxicity. In this investigation cisplatin loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles were developed and characterized for various in vitro characteristics including size distribution, zeta potential, drug loading and release profile. PLGA nanoparticles were successfully developed as investigated using scanning electron microscopy and exhibited average particles size and zeta potential as 284.8 nm and -15.8 mV, respectively. Fourier transform infrared spectroscopy and differential scanning calorimetry indicated an absence of any polymer-drug interactions. Cisplatin nanoparticles exhibited in vitro anticancer activity against A549 cells comparable to that of cisplatin solution. The biodistribution study in mice indicated that the kidney cisplatin level was significantly (p<0.01) lower with cisplatin nanoparticles than cisplatin solution. Following two cycles of cisplatin treatment, a week apart, blood urea nitrogen level was found to be higher in case of cisplatin solution as compared to cisplatin nanoparticles. Further, there was a significant (p<0.01) increase in plasma creatinine level in case of cisplatin solution as compared to cisplatin nanoparticles. Histopathological examination of kidney from cisplatin nanoparticles treated group revealed no kidney damage, however, a sign of nephrotoxicity was observed in the case of cisplatin solution. The results suggest that PLGA nanoparticle based formulation could be a potential option for cisplatin delivery.

Development and evaluation of paclitaxel loaded PLGA:poloxamer blend nanoparticles for cancer chemotherapy.

This investigation described the development of novel PLGA:poloxamer blend nanoparticles for intravenous administration of paclitaxel in order to limit the cremophor-associated adverse effects. The developed formulation was well-characterized using various techniques including scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. The nanoparticles had an average particle size around 180nm and zeta potential of -22.7mV. The in vitro release study of nanoparticles exhibited biphasic release pattern. The non-hemolytic potential of the nanoparticles indicated the suitability of the developed formulation for intravenous administration. The PLGA:poloxamer blend nanoparticles showed significantly improved cytotoxicity in cell lines (MCF-7 and Colo-205), as compared to free drug. Further, the developed formulation was stable under the accelerated storage conditions. In conclusion, the results indicated that the developed polymeric formulation is a novel and potential alternative for the paclitaxel delivery.

Synthesis, characterization and mechanistic-insight into the anti-proliferative potential of PLGA-gemcitabine conjugate.

Gemcitabine, a nucleoside analogue, is used in the treatment of various solid tumors, however, its efficacy is limited by rapid metabolism by cytidine deaminase and fast kidney excretion. In this study, a polymeric conjugate of gemcitabine was prepared by covalent coupling with poly(lactic-co-glycolic) acid (PLGA), in order to improve anticancer efficacy of the drug. The prepared conjugate was characterized by various analytical techniques including FTIR, NMR and mass spectroscopic analysis. The stability study indicated that the polymeric conjugate was more stable in plasma as compared to native gemcitabine. Further, in vitro cytotoxicity determined in a panel of cell lines including pancreatic cancer (MIAPaCa-2), breast cancer (MCF-7) and colon cancer (HCT-116), indicated that the cytotoxic activity of gemcitabine was retained following conjugation with polymeric carrier. In the nucleoside transportation inhibition assay, it was found that the prepared conjugate was not dependent on nucleoside transporter for entering into the cells and this, in turn, reflecting potential implication of this conjugate in the therapy of transporter- deficient resistance cancer. Further, the cell cycle analysis showed that the sub-G1 (G0) apoptotic population was 46.6% and 60.6% for gemcitabine and PLGA gemcitabine conjugate, respectively. The conjugate produced remarkable decrease in mitochondrial membrane potential, a marker of apoptosis. In addition, there was a marked increase in PARP cleavage and P-H2AX expression with PLGA gemcitabine conjugate as compared to native gemcitabine indicating improved apoptotic activity. The findings demonstrated the potential of PLGA gemcitabine conjugate to improve clinical outcome of gemcitabine based chemotherapy of cancer.