Therapeutic efficacy and promise of stem cell-derived extracellular vesicles in Alzheimer's disease and other aging-related disorders.

The term extracellular vesicles (EVs) refers to a variety of heterogeneous nanovesicles secreted by almost all cell types, primarily for intercellular communication and maintaining cellular homeostasis. The role of EVs has been widely reported in the genesis and progression of multiple pathological conditions, and these vesicles are suggested to serve as 'liquid biopsies'. In addition to their use as biomarkers, EVs secreted by specific cell types, especially with stem cell properties, have shown promise as cell-free nanotherapeutics. Stem cell-derived EVs (SC-EVs) have been increasingly used as an attractive alternative to stem cell therapies and have been reported to promote regeneration of aging-associated tissue loss and function. SC-EVs treatment ameliorates brain and peripheral aging, reproductive dysfunctions and inhibits cellular senescence, thereby reversing several aging-related disorders and dysfunctions. The anti-aging therapeutic potential of SC-EVs depends on multiple factors, including the type of stem cells, the age of the source stem cells, and their physiological state. In this review, we briefly describe studies related to the promising effects of SC-EVs against various aging-related pathologies, and then we focus in-depth on the therapeutic benefits of SC-EVs against Alzheimer's disease, one of the most devastating neurodegenerative diseases in elderly individuals. Numerous studies in transgenic mouse models have reported the usefulness of SC-EVs in targeting the pathological hallmarks of Alzheimer's disease, including amyloid plaques, neurofibrillary tangles, and neuroinflammation, leading to improved neuronal protection, synaptic plasticity, and cognitive measures. Cell culture studies have further identified the underlying molecular mechanisms through which SC-EVs reduce amyloid beta (Aß) levels or shift microglia phenotype from pro-inflammatory to anti-inflammatory state. Interestingly, multiple routes of administration, including nasal delivery, have confirmed that SC-EVs could cross the blood-brain barrier. Due to this, SC-EVs have also been tested to deliver specific therapeutic cargo molecule/s (e.g., neprilysin) to the brain. Despite these promises, several challenges related to quality control, scalability, and biodistribution remain, hindering the realization of the vast clinical promise of SC-EVs.

Prognostic value of hematological parameters in older adult patients with acute coronary syndrome undergoing coronary intervention: a single centre prospective study.

BACKGROUND: Cardiovascular disease is a significant contributor to the disease burden in geriatric patients. Underlying systemic inflammation is thought to be the cause of age-related changes in the bone marrow and a major risk factor for atherosclerosis. The purpose of the study was to assess the accuracy of these hematological biomarkers in predicting 30-day mortality in older patients with acute coronary syndrome (ACS). METHODS: This was a prospective observational study of 601 older adult patients (age > 60 years) with ACS who underwent percutaneous coronary intervention over two years (2017-2019). The relationship between baseline hematological parameters and mortality was assessed during the 30-day follow-up. Logistic regression analysis and receiver operating characteristic curve analysis were done to evaluate for diagnostic accuracy of various hematological parameters. RESULTS: The mean age of presentation was 77 ± 17 years. The mean neutrophil-lymphocyte ratio (NLR) value was 5.07 ± 4.90 and the mean platelet-lymphocyte ratio (PLR) value was 108.65 ± 85.82. On univariate analysis, total leucocyte count [odds ratio (OR) = 0.85, P = 0.021], hematocrit (OR = 0.91, P = 0.018), NLR (OR = 1.10, P = 0.001) and PLR (OR = 1.05, P = 0.001) were associated with mortality. On receiver operating characteristic curve analysis, NLR predicted mortality with 68.1% and PLR with 65.7% accuracy. On multivariate analysis, NLR (OR = 1.096, 95% CI: 1.006-1.15, P = 0.035) was an independent predictor of 30-day mortality. CONCLUSIONS: For the risk classification of all elderly ACS patients, we highly advise using NLR rather than the total white blood cell count.

Role of ambulatory blood pressure monitoring in hypertensive patients having controlled office blood pressure.

BACKGROUND AND OBJECTIVES: Ambulatory blood pressure (BP) monitoring has become useful in the diagnosis and management of hypertensive individuals. In this study we tried to know the role of office and ambulatory BP in treated hypertensive patients. METHODS AND PATIENTS: Prospective cohort of 561 treated hypertensive patients were enrolled in the study. Hypertension definitions were according to JNC 8 classification. Office BP and ambulatory BP monitoring was done according to defined protocol. RESULTS: From a subgroup of 158 treated hypertensive patients, 91(16.2%) patients were having white coat hypertension (p value 0.00 by Pearson chi square test). In a subset of 403 patients who were having controlled BP on the day of enrolment as well as on the day of attaching ambulatory BP monitor; 98 (17.4%) patients were having masked uncontrolled hypertension (MUCH). In addition there was very significant percentage of non-dippers and reverse dippers. In our study we found that office BP has a moderate to low specificity and sensitivity and low negative predictive value for overall control in treated hypertensive patients. CONCLUSION: Ambulatory BP monitoring should be included in the management protocol of treated hypertensive patients, for the optimal BP control.

Polycaprolactone-collagen nanofibers loaded with dexamethasone and simvastatin as an osteoinductive and immunocompatible scaffold for bone regeneration applications.

Physiological inflammation has been shown to promote bone regeneration; however, prolonged inflammation impedes the osteogenesis and bone repair process. To overcome the latter we aimed to develop a dual drug delivering nanofibrous scaffold to promote osteogenic differentiation of mesenchymal stromal cells (MSCs) and modulate the pro-inflammatory response of macrophages. The polycaprolactone (PCL)-collagen nanofibrous delivery system incorporating dexamethasone and simvastatin was fabricated by electrospinning process. The morphological analysis and mRNA, as well as protein expression of proinflammatory and anti-inflammatory cytokines in human monocytes (U937 cells), demonstrated the immunocompatibility effect of dual drug-releasing nanofibrous scaffolds. Nitric oxide estimation also demonstrated the anti-inflammatory effect of dual drug releasing scaffolds. The scaffolds demonstrated the osteogenic differentiation of adipose-derived MSCs by enhancing the alkaline phosphatase (ALP) activity and mineral deposition after 17 days of cell culture. The increased expression of Runt-related transcription factor-2 (RUNX-2) and osteocalcin at mRNA and protein levels supported the osteogenic potential of dual drug-loaded fibrous scaffolds. Hence, the results indicate that our fabricated nanofibrous scaffolds exhibit immunomodulatory properties and could be employed for bone regeneration applications after further in-vivo validation.

Dual drug-delivering polycaprolactone-collagen scaffold to induce early osteogenic differentiation and coupled angiogenesis.

Bone regeneration is a multi-step, overlapping process, in which angiogenesis and osteogenesis are the key players. Several attempts have been made to promote angiogenesis-coupled osteogenesis using scaffolding technology. However, the recreation of functional vasculature during bone regeneration is an unparalleled challenge. In this study, a dual drug-delivering polycaprolactone-collagen fibrous scaffold is reported to promote early osteogenesis and angiogenesis. Simvastatin as a pro-angiogenic and dexamethasone as an osteoinductive drug were encapsulated to functionalize the electrospun fibers. The optically transparent fibrous mat represented the sustained and sequential release of drugs for 28 days. The fibrous mesh increased cell proliferation and enhanced the osteogenic differentiation up to 21 days. The alkaline phosphatase activity and mineral deposition were comparatively higher on dual drug-releasing fibers when compared to control fibers. The dual drug-releasing osteoconductive fibers demonstrated osteogenesis as early as 7 days with a 3.7 and 1.5 fold increase in the expression of osteogenic differentiation markers (RUNX2 and osteocalcin), respectively. In vitro angiogenesis using primary human umbilical vein endothelial cells (pHUVECs) showed no significant difference in cell proliferation among control fibers and dual drug-releasing fibers. However, the angioinductive nature of simvastatin released from the fibers demonstrated tube formation and 2 fold higher angiogenic score. The mRNA and protein expression study of angiogenic markers (VEGFR2 and eNOS) by polymerase chain reaction and western blotting depicted the angioinducing potential of dual drug-releasing fibers. VEGFR2 and eNOS mRNA expressions increased by 1.1 and 1.6 fold, respectively, whereas their protein expression increased by 3.2 and 1.7 fold, respectively. The overall results demonstrate the synergistic effect of osteoconductive substrate and osteoinductive dual drugs to promote early osteogenesis, and release of the pro-angiogenic drug promotes angiogenesis.

Extracellular matrix mimicking polycaprolactone-chitosan nanofibers promote stemness maintenance of mesenchymal stem cells via spheroid formation.

The development of clinical applications has led to a perpetual increase in the demand for mesenchymal stem cells (MSCs). However, the ex vivo expansion of MSCs while maintaining their stemness and differentiation potential remains an immense challenge. MSCs require high cell density for their intercellular communication and specific physico-chemical cues from the surrounding environment for spheroid formation in order to maintain their stemness. Inadequacy of the traditional in vitro cell culture method (tissue culture plastic surface) to fulfill any of these special requirements is responsible for inducing the loss of stem cell properties of the MSCs over time. In this study, we propose that glucosaminoglycan (GAG) mimicking ultrafine nanofibers could support the spheroid culture for in vitro human MSC expansion. The geometrical and biochemical properties of nanofibers provide biomimicking cues to MSCs, as well as enhance cell-cell interactions and stimulate spheroid formation in MSCs, which subsequently result in increased cell proliferation, enhanced expression of stem cell markers and maintenance of their multilineage differentiation potential. Furthermore, close monitoring of the behavior of MSCs on nanofibers serves as the key to understand their mode of action in niche formation. Interestingly, GAG mimicking substrate stimulated MSCs for long-distance intercellular communication via 'tunneling tubes', their subsequent migration and niche formation. These kinds of cellular interactions over long distances have rarely been observed in MSCs to provide better insight for future studies on MSC niche. Furthermore, PCL-CHT nanofibers were observed to be as conducive to use as tissue culture polystyrene for stem cell expansion. Overall, these polymeric nanofibers provide a more relevant, convenient and more suitable substrate than the conventional monolayer culture for in vitro MSC expansion.

Fabrication of multifunctional cellulose/TiO2 /Ag composite nanofibers scaffold with antibacterial and bioactivity properties for future tissue engineering applications.

In the present work, a novel strategy was explored to fabricate nanofiber scaffolds consisting of cellulose assimilated with titanium dioxide (TiO2 ) and silver (Ag) nanoparticles (NPs). The concentration of the TiO2 NPs in the composite was adjusted to 1.0, 1.5, and 2.0 wt % with respect to polymer concentration used for the electrospinning of colloidal solutions. The fabricated composite scaffolds were dispensed to alkaline deacetylation using 0.05 M NaOH to remove the acetyl groups in order to generate pure cellulose nanofibers containing TiO2 NPs. Moreover, to augment our nanofiber scaffolds with antibacterial activity, the in situ deposition approach of using Ag NPs was utilized with varied molar concentrations of 0.14, 0.42, and 0.71 M. The physicochemical properties of the nanofibers were identified by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and contact angle meter studies. This demonstrated the presence of both TiO2 and Ag NPs and complete deacetylation of nanofibers. The antibacterial efficiency of the nanofibers was scrutinized against Escherichia coli and Staphylococcus aureus, revealing proper in situ deposition of Ag NPs and confirming the nanofibers are antibacterial in nature. The biocompatibility of the scaffolds was accustomed using chicken embryo fibroblasts, which confirmed their potential role to be used as wound-healing materials. Furthermore, the fabricated scaffolds were subjected to analysis in simulated body fluid at 37°C to induce mineralization for future osseous tissue integration. These results indicate that fabricated composite nanofiber scaffolds with multifunctional characteristics will have a highest potential as a future candidate for promoting new tissues artificially.

Dual functional approaches for osteogenesis coupled angiogenesis in bone tissue engineering.

Bone fracture healing is a multistep and overlapping process of inflammation, angiogenesis and osteogenesis. It is initiated by inflammation, causing the release of various cytokines and growth factors. It leads to the recruitment of stem cells and formation of vasculature resulting in the functional bone formation. This combined phenomenon is used by bone tissue engineers from past few years to address the problem of vasculature and osteogenic differentiation during bone regeneration. In this review, we have discussed all major studies reporting the dual functioning approach to promote osteogenesis coupled angiogenesis using various scaffolds. These scaffolds are broadly classified into four types based on the nature of their structural and functional components. The functionality of the scaffold is either due to the structural components or the loaded cargo which conducts or induces the coupled functionality. Dual delivery system for osteoinductive and angioinductive factors ensures the co-delivery of two different types of molecules to induce osteogenesis and angiogenesis. Single delivery scaffold for angioinductive and osteoinductive molecule releases single type of molecules which could induce both angiogenesis and osteogenesis. Osteoconductive scaffold consisted of bone constituents releases angioinductive factors. Osteoconductive and angioconductive scaffold composed of components which provide the native substrate features for osteogenesis and angiogenesis. This review article also discusses the studies highlighting the synergism of physico-chemical stimuli as dual functioning feature to enhance angiogenesis and osteogenesis simultaneously. In addition, this article covers one of the least discussed area of the bone regeneration i.e. 'cartilage formation as a median between angiogenesis and osteogenesis'.

Antioxidative study of Cerium Oxide nanoparticle functionalised PCL-Gelatin electrospun fibers for wound healing application.

Skin wound healing involves a coordinated cellular response to achieve complete reepithelialisation. Elevated levels of reactive oxygen species (ROS) in the wound environment often pose a hindrance in wound healing resulting in impaired wound healing process. Cerium oxide nanoparticles (CeNPs) have the ability to protect the cells from oxidative damage by actively scavenging the ROS. Furthermore, matrices like nanofibers have also been explored for enhancing wound healing. In the current study CeNP functionalised polycaprolactone (PCL)-gelatin nanofiber (PGNPNF) mesh was fabricated by electrospinning and evaluated for its antioxidative potential. Wide angle XRD analysis of randomly oriented nanofibers revealed ∼2.6 times reduced crystallinity than pristine PCL which aided in rapid degradation of nanofibers and release of CeNP. However, bioactive composite made between nanoparticles and PCL-gelatin maintained the fibrous morphology of PGNPNF upto 14 days. The PGNPNF mesh exhibited a superoxide dismutase (SOD) mimetic activity due to the incorporated CeNPs. The PGNPNF mesh enhanced proliferation of 3T3-L1 cells by ∼48% as confirmed by alamar blue assay and SEM micrographs of cells grown on the nanofibrous mesh. Furthermore, the PGNPNF mesh scavenged ROS, which was measured by relative DCF intensity and fluorescence microscopy; and subsequently increased the viability and proliferation of cells by three folds as it alleviated the oxidative stress. Overall, the results of this study suggest the potential of CeNP functionalised PCL-gelatin nanofibrous mesh for wound healing applications.

PCR-RFLP based genotyping of Indian isolates of Toxoplasma gondii.

Toxoplasma gondii is an apicomplexan parasite capable of infecting a wide variety of warm-blooded animals, including birds and humans and is zoonotically important too. Felidae serve its definitive hosts and most infections are inoccous while in various intermediate hosts (e.g. sheep), it is responsible for abortion, still births. Humans which are immune compromised are also susceptible to toxoplasmosis. Most of the epidemiological studies have revealed it to be belonging to three clonal types with exceptions in South Africa having atypical isolates. Current genotyping was carried out at 11 genetic loci (SAG1, 5'-SAG2, 3'-SAG2, alt. SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358 and PK1) using multiplex-nested polymerase chain reaction restriction fragment length polymorphism (Mn-PCR-RFLP). SAG1, alt SAG2, SAG3, BTUB, GRA6, C22-8, C29-2, L358 and PK1 could differentiate our strain/isolates as type I (T. gondii RH) and type III (T. gondii isolates from Chennai and Izatnagar). 5'SAG2 and 3'SAG2 in combination confirmed these as above mentioned genotypes. Further, the T. gondii RH was assigned Toxo DB#10 and local isolates of T. gondii were assigned Toxo DB#2. The present study is the first report on existence of Type III T. gondii lineage from animal population of Indian subcontinent based on PCR-RFLP.

Shoshin beriberi-thiamine responsive pulmonary hypertension in exclusively breastfed infants: A study from northern India.

OBJECTIVE: To study the effect of thiamine administration on the resolution of pulmonary hypertension in exclusively breastfed infants. DESIGN: Prospective cohort study. SETTING: Hospital based study of a tertiary care hospital. PATIENTS: A total of 29 infants with 17 males (58.6%) and 12 females (41.4%) were included in the study. INTERVENTION: In addition to the management of shock, right heart failure and renal failure, patients received intravenous thiamine 100mg/kg IV followed by 10mg/day till introduction of supplementary feeds. MAIN OUTCOMES MEASURES: Resolution of shock, metabolic complications and pulmonary hypertension. RESULTS: Mean age at presentation was 78.45±30.7 days. All infants were exclusively breastfed. 86.2% of mothers were on customary dietary restrictions. Biventricular failure and tachycardia was commonly present. There were four deaths in our series. Acute metabolic acidosis was a universal feature with a mean pH of 7.21±0.15. Pulmonary hypertension was present in all patients on admission. Intravenous thiamine 100mg/kg IV stat was given immediately after documenting pulmonary hypertension. Repeat echocardiography showed complete resolution of pulmonary hypertension. CONCLUSION: Many infants present to us with Shoshin beriberi with unusually high pulmonary pressures. These patients respond to thiamine challenge with prompt resolution of metabolic complications and reversal of pulmonary hypertension. We believe this is first of its kind from the region, which is reported.

Transradial versus transfemoral approach for coronary angiography and angioplasty - A prospective, randomized comparison.

BACKGROUND: PCI has been done traditionally through transfemoral route. But now transradial and transbrachial routes are also coming up in practice. We compared transradial versus transfemoral routes for ease of operability, time for procedure, complications, and failure rates through a prospective study. METHODS: Four hundred Patients admitted in department of cardiology for percutaneous interventions were enrolled in the study. 200 patients were assigned to each group randomly. A single team did all the procedures. Pre procedure, intra procedure and post procedure data of all the patients was collected, tabulated and analysed properly. RESULTS: Access time (6.0 ± 1vs 4.2 ± 0.7; P =0.001); Fluoroscopy time and overall procedure time (29 ± 11.3 Vs. 27.3 ± 12.4 min) were more with trans radial than transfemoral route, respectively. The most common post procedure complication, ecchymosis was seen in 20.5% in transfemoral group compared to 12.5% in transradial group (P 0.031). Thrombophelibites (17.5 VS 8%, P0.004); Hematoma (14.5 Vs 0%, P 0.005); post procedure access bleed (7 VS 3%, P 0.039) were seen in transfemoral than transradial group, respectively. Failure rates were almost similar. None of our patients had post procedure myocardial infarction, stroke, acute renal failure and infections. CONCLUSION: Transradial approach of PCI is better than transfemoral route with respect to complications like bleeding, haematoma formation, thrombophelebites and ecchymosis is concerned. However access and fluoroscopic time is more with the former. We recommend the transradial route for PCI. TRIAL REGISTRATION: Trial is retrospectively registered in ClinicalTrials.gov with the Identifier: NCT02983721 , Date of registration is December 2, 2016.

A comparative study on the effect of amiodarone and metaprolol for prevention of arrythmias after open heart surgery.

OBJECTIVES: The aim of this study was to compare the effect of amiodarone and metaprolol in prevention of atrial fibrillation in patients, following open heart surgery. METHODS: This prospective study was carried out between May 2008 to Nov. 2010, and comprised a total of 50 patients with normal preoperative sinus rhythm undergoing open heart surgery using cardio pulmonary bypass. RESULTS: Mean age of patients was 47+2.7 years, of which 60% who developed atrial fibrillation aged from 51 to 60 years. Most patients (62%) were in NYHA Class III. Patients who received amiodarone showed significant improvement in LVEF compared to those treated with Metaprolol. Amiodarone treated group exhibited lesser incidence and short-lasting atrial fibrillation, lower ventricular rate, shorter hospitalization, and lesser cost of care than those in metaprolol group. CONCLUSIONS: The present study showed that amiodarone was more efficient in controlling post-operative atrial fibrillation as compared to metaprolol. However, a larger randomized controlled trial is needed to corroborate the result of this study.