Sex-based impact of pancreatic islet stressors in GluCreERT2/Rosa26-eYFP mice

The present study examines differences in metabolic and pancreatic islet adaptative responses following streptozotocin (STZ) and hydrocortisone (HC) administration in male and female transgenic GluCreERT2/Rosa26-eYFP mice. Mice received five daily doses of STZ (50 mg/kg, i.p.) or 10 daily doses of HC (70 mg/kg, i.p.), with parameters assessed on day 11. STZ-induced hyperglycaemia was evident in both sexes, alongside impaired glucose tolerance and reduced insulin concentrations. HC also had similar metabolic effects in male and female mice resulting in classical increases of circulating insulin indicative of insulin resistance. Control male mice had larger pancreatic islets than females and displayed a greater reduction of islet and beta-cell area in response to STZ insult. In addition, female STZ mice had lower levels of beta-cell apoptosis than male counterparts. Following HC administration, female mouse islets contained a greater proportion of alpha cells when compared to males. All HC mice presented with relatively comparable increases in beta- and alpha-cell turnover rates, with female mice being slightly more susceptible to HC-induced beta-cell apoptosis. Interestingly, healthy control female mice had inherently increased alpha-to-beta-cell transdifferentiation rates, which was decreased by HC treatment. The number of glucagon-positive alpha cells altering their lineage to insulin-positive beta cells was increased in male, but not female, STZ mice. Taken together, although there was no obvious sex-specific alteration of metabolic profile in STZ or HC mice, subtle differences in pancreatic islet morphology emphasises the impact of sex hormones on islets and importance of taking care when interpreting observations between males and females.

The glucagon receptor antagonist desHis1Pro4Glu9-glucagon(Lys12PAL) alters alpha-cell turnover and lineage in mice, but does not cause alpha-cell hyperplasia

OBJECTIVE

Glucagon receptor (GCGR) antagonism elicits antihyperglycemic effects in rodents and humans. The present study investigates whether the well characterised peptide-based GCGR antagonist, desHis¹Pro⁴Glu⁹-glucagon (Lys¹²PAL), alters alpha-cell turnover or identity in mice.

METHODS

Multiple low-dose streptozotocin (STZ) treated (50 mg/kg bw, 5 days) transgenic Glu^CreERT2;ROSA26-eYFP mice were employed. STZ mice received twice daily administration of saline vehicle or desHis¹Pro⁴Glu⁹-glucagon (Lys¹²PAL), at low- or high-dose (25 and 100 nmol/kg, respectively) for 11 days.

RESULTS

No GCGR antagonist induced changes in food or fluid intake, body weight or glucose homeostasis were observed. As expected, STZ dramatically reduced (P < 0.001) islet numbers and increased (P < 0.01) alpha-to beta-cell ratio, which was linked to elevated (P < 0.05) levels of beta-cell apoptosis. Whilst treatment with desHis¹Pro⁴Glu⁹-glucagon (Lys¹²PAL) decreased (P < 0.05-P < 0.001) alpha- and beta-cell areas, it also helped restore the classic rodent islet alpha-cell mantle in STZ mice. Interestingly, low-dose desHis¹Pro⁴Glu⁹-glucagon (Lys¹²PAL) increased (P < 0.05) alpha-cell apoptosis rates whilst high dose decreased (p < 0.05) this parameter. This difference reflects substantially increased (P < 0.001) alpha-to beta-cell transdifferentiation following high dose desHis¹Pro⁴Glu⁹-glucagon (Lys¹²PAL) treatment, which was not fully manifest with low-dose therapy.

CONCLUSIONS

Taken together, the present study indicates that peptidic GCGR antagonists can positively influence alpha-cell turnover and lineage in identity in multiple low-dose STZ mice, but that such effects are dose-related.

SARS-CoV-2 infection is associated with increased odds of insomnia, RLS and dream enactment behavior

BACKGROUND

Literature suggests that the COVID-19 pandemic has resulted in poor sleep quality, especially among the infected population. However, literature regarding the effect of COVID-19 pandemic and SARS-CoV-2 infection on occurrence of insomnia, restless legs syndrome and dream enactment behavior is either scarce or unavailable.

METHODS

This study was planned to assess the effect of SARS-CoV-2 infection on the occurrence of insomnia, restless legs syndrome (RLS) and dream enactment behavior (DEB). For this cross-sectional study, a questionnaire comprising of items related to demographic details, past medical history, and information related to SARS-CoV-2 infection was distributed through social media. Insomnia was diagnosed using clinical criteria. RLS, DEB, sleep quality, depression and anxiety were assessed using a validated questionnaire. Information regarding the use of hypnotic medications was also gathered.

RESULTS

Of the 1596 respondents, 37.2% reported disturbed sleep while insomnia was reported by 22.6% respondents. 27.3% of respondents reported RLS and 17.4% suffered DEB. The odds of insomnia were greater among males (OR = 1.27; 95% CI: 1.03-1.58; P < 0.02) and among those who had SARS-CoV-2 infection (OR = 1.76; 95% CI = 1.42-2.19; P < 0.001). Similarly, SARS-CoV-2 infection was also associated with increased odds of RLS (OR = 2.48; 95% CI = 1.98-3.11; P < 0.001) and DEB (OR = 1.58; 95%CI = 1.21-2.06; P < 0.001). Insomnia, RLS and DEB were more frequent among respondents who required oxygen therapy, those who experienced loss of taste and/or smell, depression and anxiety. Prevalence of insomnia, DEB and RLS was higher than said prevalence among respondents with no history of SARS-CoV-2 infection, but lower than that of those with positive history of SARS-CoV-2 infection. 5.3% of respondents reported taking hypnotic medications before infection, 7% during infection and 5.3% after infection.

CONCLUSION

SARS-CoV-2-infection-related factors in association with environmental factors have increased the prevalence of insomnia, DEB and RLS among subjects having infection. SARS-CoV-2-associated immunological changes, hypoxia and neurotropism may play a role in occurrence of insomnia, DEB and RLS.

386 Proximal Femoral Nail (PFN) Versus Dynamic Hip Screw (DHS) In Unstable Intertrochanteric Fractures of Femur -A Comparative Clinical Study

Introduction

The goal of treatment of an intertrochanteric femoral fracture is restoration of patient's mobility as early as possible. The dynamic hip screw (DHS) has been used for several decades to treat these fractures. Proximal femoral nails (PFN) are reported to have an advantage in such fractures. This study aims at comparing the results of unstable intertrochanteric fractures femur treated with PFN and DHS.

Method

This was a prospective, randomized study which includes sixty patients. All patients were available for follow up with 30 patients in each group. The data about intraoperative blood loss, time to union, leg length shortening was collected. The functional outcome at the end of one year was evaluated using Harris Hip Score.

Results

Blood loss, duration of surgery, time to union and leg length shortening was significantly less in the patients treated with PFN (p &lt; 0.05). The mean harris hip score for patients managed with PFN was significantly more than in DHS group, 12 months after surgery (p = 0.05).

Conclusions

PFN requires a smaller incision, lesser operative time, less blood loss and has improved functional results. In our opinion PFN may be a better fixation device for most of the unstable intertrochanteric femur fractures.

Changes in sleep pattern and sleep quality during COVID-19 lockdown

INTRODUCTION

To mitigate the spread of the pandemic coronavirus infection (COVID-19), governments across the world have adopted "lockdowns" which have confined many individuals to their homes. This disrupts normal life routines, elements of which are important circadian cues. The pandemic is also associated with new stressors, altered roles, and uncertainties about health and economic security, which are also likely to affect sleep. The current study is an online survey of sleep experience, routines, physical activity, and symptoms of anxiety and depression, to study the alterations associated with the lockdown.

MATERIALS AND METHODS

The survey was conducted in early May 2020 using a questionnaire circulated through social media platforms. Questions related to demographic characteristics, current and previous sleep schedules, routine, and working patterns. Insomnia (Insomnia Severity Index - 4), Stress (Perceived Stress Scale - 4), anxiety and depressive symptoms (Patient Health Questionnaire - 4) and physical activity (International Physical Activities Questionnaire) were assessed using standardized instruments.

RESULTS

A total of 958 valid responses were received. Compared to the prelockdown period, there was a shift to a later bedtime and waking time, with a reduction in night-time sleep and an increase in day-time napping. These effects were visible across occupational groups, but mostly affected working individuals except health professionals. Sleep quality deteriorated across groups. Reductions in sleep duration were associated with depressive symptoms.

CONCLUSIONS

The COVID-19 lockdown is associated with changes in sleep schedule and in the quantity and quality of night-time sleep. Although these changes are associated with elevated rates of emotional symptoms, it is unclear from these cross-sectional results, whether sleep deterioration produces psychological distress, or vice versa.

Skindex-29 to Determine Quality of Life and Emotional Factors in Dermatological Conditions

Though rarely fatal, skin diseases are known to be associated with increased psychiatric morbidity and considerable impairment of quality of life (QoL). Health Related Quality of Life (HRQoL) in skin diseases can be assessed by generic or skin specific instruments. One hundred sixty patients with a range of dermatological diagnoses were studied on a cross sectional observational paradigm. Skindex29, a skin specific instrument, was used to assess QoL, while anxiety and depression were assessed by Anxiety Status Inventory (ASI) and Depression Status Inventory (DSI), respectively. Sixty two patients (39%) had impaired QoL out of which 37(60%) had severe impairment. 11 patients (7%) had anxiety and 22(14%) had depression in the mild to moderate range. Gender, anxiety, depression and effect on appearance seem to be not related to impaired QoL. Further large scale studies are needed to ascertain the factors impinging on the QoL of dermatologically ill patients.

A study of sociodemographic clinical and glycemic control factors associated with co-morbid depression in type 2 diabetes mellitus

CONTEXT

Diabetes affects 9.2% of adults in India. About 8-16% of its population also suffer from depression. Both diseases pose a serious health challenge at individual and system level. The prevalence of depression in diabetes is much higher than in the general population. Undiagnosed and untreated depression puts people at higher morbidity and mortality risk.

AIM

To study the prevalence of depression in diabetes and to identify associated risk factors.

SETTINGS AND DESIGN

Case control study carried out in an outpatient setting of a tertiary hospital in central India.

MATERIALS AND METHODS

One hundred and nine type 2 diabetes patients and 91 healthy controls formed the subjects of the study. Sociodemographic data were obtained on seven parameters. Comprehensive clinical data were obtained by means of standard procedures. Blood sugar levels and glycosylated hemoglobin levels were measured to assess glycemic control. Data of diabetic patients and controls as well as that of depressed and nondepressed diabetics were subjected to statistical analysis.

RESULTS

About 42.2% of diabetes patients and only 4.39% of controls had depression. About 19% of diabetics had peripheral neuropathy but had much higher neuropathic symptoms. Depression was not related to any sociodemographic or clinical factors but was strongly associated with poor glycemic control.

CONCLUSION

Depression is highly prevalent in diabetes. Physical symptoms mask depression. Special attention needs to be paid to diagnose depression in diabetes and treat it appropriately along with effective glycemic control. Diabetes patients need to be treated collaboratively by physicians and psychiatrists.

Neurocognitive impairment and comorbid depression in patients of diabetes mellitus

This study was conducted to find out the association of diabetes mellitus with cognitive functioning and depressive features. We included 50 diabetic and 30 control subjects who were screened on the basis of various inclusion and exclusion criteria. Then, a history of variables under study was taken and respective laboratory investigations were noted. First, the Becks Depression Inventory (BDI) was administrated to the patients. The cognitive function was then assessed using the digit span test, stroop Test, controlled oral word association test, visual target cancellation test, digit symbol substitution test, and visuospatial working memory matrix. The composite score on all tests was used to make cognitive index. The data was compiled and appropriate statistical methods were used. We found that 48% of elderly diabetic patients showed cognitive impairment. Poor metabolic control (hyperglycemia) was associated significantly and negatively with cognitive index in diabetic patients. Hyperglycemia was significantly and negatively correlated with immediate memory and attention, verbal memory, psychomotor functioning (DSST), and visuospatial memory. In conclusion, genesis of cognitive deficits in diabetic patients is complex. However, it appears from the study that such deficits do exist and may be associated with chronically poorly controlled diabetes.

Evaluation of Solid Lipid Nanoparticles as Carriers for Delivery of Hepatitis B Surface Antigen for Vaccination Using Subcutaneous Route

Purpose: Solid lipid nanoparticles (SLN) have emerged as carriers for therapeutic peptides, proteins, antigens and bioactive molecules. We have explored the potential of SLN as carrier for Hepatitis B surface antigen (HBsAg) by surface modifications to enhance their loading efficiency and the cellular uptake, using subcutaneous route. Methods: Four different formulations of SLN were prepared by solvent injection method and characterized for various physical properties: particle size, surface morphology, shape, zeta potential, polydispersity, X-ray diffraction analysis, release profile and entrapment efficiency. HBsAg loaded SLN were studied for their functional characteristics, in vitro cellular uptake and internalization studies by human dendritic cells, macrophages and fibroblasts, T cell proliferation and TH1/TH2 response. Humoral immune response elicited by subcutaneously administered HBsAg containing SLN formulations were studied in vivo in mice. Results: Compared to soluble HBsAg; SLN, particularly the mannosylated formulation, showed better cellular uptake, lesser cytotoxicity and induction of greater TH1 type of immune response. They also showed better immunological potential by producing sustained antibody titer. Conclusion: Mannosylated SLN appears to be promising as carrier for vaccine delivery against hepatitis B as ascertained by in vitro and in vivo studies, however further investigations on humans are required to establish their potential as vaccines against hepatitis B infection.

In vitro evaluation of surface functionalized gelatin nanoparticles for macrophage targeting in the therapy of visceral leishmaniasis

The present study evaluates the potential of surface functionalized gelatin nanoparticles (f-GNPs) for efficient macrophage-specific delivery of amphotericin B (AmB) in the treatment of visceral leishmaniasis (VL). Further, the effect of spacer for macrophage targeting was also evaluated. Gelatin was functionalized either through conjugation to mannose via direct coupling (mGelatin) or via PEG spacer (m-Gelatin), and the synthesis was confirmed by FTIR. AmB-loaded f-GNPs, that is, mGNPs and m-GNPs prepared from mGelatin and m-Gelatin conjugates, respectively, were characterized. In vitro concanavalin A (Con-A) agglutination assay confirmed the availability of mannose on the surface of these f-GNPs. Kinetics of cellular uptake of AmB-loaded f-GNPs by J774A.1 macrophage cells assessed through flow cytometry demonstrated a steady increase and maximum cell-associated fluorescence was observed at 4h for m-GNPs and 6 h for m-GNPs. Measurement of cytotoxicity using Annexin-V-FITC/PI apoptosis assay delineated marginal changes (7-9%) in treated macrophages following 48 h incubation, establishing the safety of f-GNPs. m-GNPs showed a 5.4-fold reduction in IC(50) in comparison with plain AmB suggesting significant enhancement of antileishmanial activity. Our results indicate that f-GNPs could be a promising carrier for specific delivery of AmB to macrophages for effective treatment of VL. Furthermore, spacer contributed significantly in reducing the cytotoxicity as well as increasing the uptake and activity of f-GNPs.

Carbohydrate-conjugated multiwalled carbon nanotubes: development and characterization

This work presents a novel cascade of chemical functionalization of multiwalled carbon nanotubes (MWCNTs) through chemical modification by a carbohydrate, D-galactose. Galactose-conjugated or galactosylated MWCNTs were synthesized involving the sequential steps of carboxylation, acylation, amine modification, and finally, galactose conjugation. The modification of MWCNTs with galactose was investigated by elemental analysis, x-ray diffraction analysis, Fourier transform-infrared spectroscopy, Raman spectroscopy, and zeta potential measurements, at every sequential step of functionalization. Size and surface characteristics of chemically modified MWCNTs were monitored by transmission electron microscopy and scanning electron microscopy. That galactosylation improved the dispersibility of MWCNTs in aqueous solvents was confirmed by investigation of their dispersion characteristics at different pH values. Thus, the galactosylated MWCNTs as developed could be used for delivery of different bioactive(s) as well as active ligand (galactose)-based targeting to hepatic tissue.

FROM THE CLINICAL EDITOR

This work presents a novel cascade of functionalization of multiwalled carbon nanotubes (MWCNTs) through chemical modification by a carbohydrate. Galactosylation improves the dispersibility of MWCNTs in aqueous solvents. The galactosylated MWCNTs could be used for delivery of different bioactive(s) as well as active ligand-based targeting to hepatic tissue.

Dermal and transdermal delivery of an anti-psoriatic agent via ethanolic liposomes

The aim of the current investigation is to evaluate the transdermal potential of novel vesicular carrier, ethosomes, bearing methotrexate (MTX), an anti-psoriatic, anti-neoplastic, highly hydrosoluble agent having limited transdermal permeation. MTX loaded ethosomes were prepared, optimized and characterized for vesicular shape and surface morphology, vesicular size, entrapment efficiency, stability, in vitro human skin permeation and vesicle-skin interaction. The formulation (EE(9)) having 3% phospholipid content and 45% ethanol showing the greatest entrapment (68.71+/-1.4%) and optimal nanometric size range (143+/-16 nm) was selected for further transdermal permeation studies. Stability profile of prepared system assessed for 120 days revealed very low aggregation and growth in vesicular size (8.8+/-1.2%). MTX loaded ethosomal carriers also provided an enhanced transdermal flux of 57.2+/-4.34 microg/cm(2)/h and decreased lag time of 0.9 h across human cadaver skin. Skin permeation profile of the developed formulation further assessed by confocal laser scanning microscopy (CLSM) revealed an enhanced permeation of Rhodamine Red (RR) loaded formulations to the deeper layers of the skin (170 microm). Also, the formulation retained its penetration power after storage. Vesicle skin interaction study also highlighted the penetration enhancing effect of ethosomes with some visual penetration pathways and corneocytes swelling, a measure of retentive nature of formulation. Our results suggests that ethosomes are an efficient carrier for dermal and transdermal delivery of MTX.

Evaluation of uptake and generation of immune response by murine dendritic cells pulsed with hepatitis B surface antigen-loaded elastic liposomes

Hepatitis B surface antigen (HBsAg)-loaded elastic liposomes were studied for qualitative and quantitative uptake in vitro by murine dendritic cells (DCs) generated from bone marrow mononuclear cells. Internalization of the vesicles by the DCs was documented using fluorescence microscopy. Kinetics of uptake of antigen-loaded elastic vesicles by the DCs studied through flow cytometry showed a peak uptake at 6h. The ability of the antigen pulsed DCs to stimulate autologous peripheral blood lymphocytes was demonstrated by BrdU assay. Further evaluation by multiplex cytometric bead array analysis demonstrated a predominantly TH1 type of immune response. Our results suggest that HBsAg-loaded elastic vesicles as antigen delivery module and DCs as antigen presenting cells are able to generate a protective immune response. The property of elastic liposomes to traverse and target the immunological milieu of the skin makes it an attractive vehicle for development of a transcutaneous vaccine against hepatitis B virus.

Enhanced Oromucosal Delivery of Progesterone Via Hexosomes

PURPOSE

Formulation and characterization of progesterone loaded hexosomes employing a novel method for oromucosal delivery.

METHOD

Hexosomes were prepared employing a method in which ethanolic solution of lipid phase (monolein and oleic acid) was vortexed with aqueous phase (surfactant solution) and characterized for particle size, morphology and internal structure. FT-IR and confocal laser scanning microscopy (CLSM) were performed to investigate the possible mechanism and penetration pathway of hexosomes within the mucosa.

RESULTS

Hexosomes exhibited anisotropy, hexagonal shape and nanometric size (251.2+/-1.8 nm). Internal structure confirmed by X-ray diffraction peaks with spacing ratio of radical1:radical3:radical4 proved two-dimensional hexagonal arrangements. Entrapment efficiency of system was greater than 95%. In vitro release studies revealed an enhanced transmucosal flux (4.67+/-0.14 microg cm(-2) h(-1)) and decreased lag time (1.54 h) across albino rabbit mucosa. FT-IR and CLSM of treated mucosa shows lipid extraction phenomena as well as structural irregularities within intercellular lipids respectively. These irregularities can function as 'virtual channels' facilitating hexosome's penetration.

CONCLUSION

Developed hexosomes formulation exhibited high entrapment efficiency, high permeability and better stability on storage, thus proposing itself a novel carrier for enhanced oromucosal delivery of progesterone.

Melatonin loaded ethanolic liposomes: physicochemical characterization and enhanced transdermal delivery

The current investigation aims to evaluate the transdermal potential of novel ethanolic liposomes (ethosomes) bearing Melatonin (MT), an anti-jet lag agent associated with poor skin permeation and long lag time. MT loaded ethosomes were prepared and characterized for vesicular shape and surface morphology, vesicular size, entrapment efficiency, stability, in vitro skin permeation and in vivo skin tolerability. Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), and Dynamic Light Scattering (DLS) defined ethosomes as spherical, unilamellar structures having low polydispersity (0.032+/-0.011) and nanometric size range (122+/-3.5 nm). % Entrapment efficiency of MT in ethosomal carrier was found to be 70.71+/-1.4. Stability profile of prepared system assessed for 120 days revealed very low aggregation and growth in vesicular size (7.6+/-1.2%). MT loaded ethosomal carriers also provided an enhanced transdermal flux of 59.2+/-1.22 microg/cm2/h and decreased lag time of 0.9 h across human cadaver skin. Fourier Transform-Infrared (FT-IR) data generated to assess the fluidity of skin lipids after application of formulation revealed a greater mobility of skin lipids on application of ethosomes as compared to that of ethanol or plain liposomes. Skin permeation profile of the developed formulation further assessed by confocal laser scanning microscopy (CLSM) revealed an enhanced permeation of Rhodamine Red (RR) loaded formulations to the deeper layers of the skin (240 microm). Further, a better skin tolerability of ethosomal suspension on rabbit skin suggested that ethosomes may offer a suitable approach for transdermal delivery of melatonin.

Elastic liposomes mediated transdermal delivery of an anti-hypertensive agent: propranolol hydrochloride

One major problem encountered in transdermal drug delivery is the low permeability of drugs through the skin barrier. In the present investigation ultradeformable lipid vesicles, that is, elastic liposomes were prepared incorporating propranolol hydrochloride for enhanced transdermal delivery. Elastic liposomes bearing propranolol hydrochloride were prepared by conventional rotary evaporation method and characterized for various parameters including vesicles shape and surface morphology, size and size distribution, entrapment efficiency, elasticity, turbidity, and in vitro drug release. In vitro flux, enhancement ratio (ER), and release pattern of propranolol hydrochloride were calculated for transdermal delivery. In vivo study conducted on male albino rats (Sprague Dawley) was also taken as a measure of performance of elastic liposomal, liposomal, and plain drug solution. The better permeation through the skin was confirmed by confocal laser scanning microscopy (CLSM). Results indicate that the elastic liposomal formulation for transdermal delivery of propranolol hydrochloride provides better transdermal flux, higher entrapment efficiency, ability as a self-penetration enhancer and effectiveness for transdermal delivery as compared to liposomes.

Association of hypertension and its treatment with dementia and cognitive functioning

AIM

Hypertension is known to induce many pathological changes in the body, including cardiac hypertrophy, atherosclerosis, micro-aneurisms and stroke. Besides these conspicuous pathologies, it also has subtle effects on the functioning of the brain. These cognitive changes have received little attention despite the fact that they make a large impact on the daily functioning of affected persons. The present study was conducted to assess the effect of hypertension and related factors on cognitive functions in an Indian population.

METHODS AND RESULTS

A cohort of young hypertensive subjects was recruited after obtaining informed consent. Subjects with confounding factors, such as substance use, neurological disorders, endocrinopathies, inflammatory conditions and psychiatric illnesses, were excluded. The average systolic and diastolic blood pressure of the subjects since the onset of illness and prescription of drugs were noted from the records. Compliance was assessed with the help of information given by the subjects and their close relatives. The mini-mental state examination and a battery of neuropsychological tests (digit span test, trail making test, Stroop test, visuospatial working memory matrix and word fluency test) were applied to all participants. Univariate regression analysis was used for the assessment of association and a one-way analysis of variance was performed on categorical variables. The mean age of the subjects was 52 years, and the average duration of hypertension 9 years. Twelve subjects had dementia which could be attributed to the subtle effects of hypertension only. Blood pressure (both systolic and diastolic) had a significant negative association with the cognitive tests. Cognitive impairment was also seen in subjects who reported poor drug compliance and those using beta blockers, while calcium channel blockers played a protective role.

CONCLUSIONS

Hypertension was associated with a significant decline in cognitive functioning in younger subjects. Good compliance with drugs and the use of calcium channel blockers had a protective effect on hypertension-induced cognitive decline.

Elastic liposomes mediated transcutaneous immunization against Hepatitis B

Transcutaneous immunization presents a major challenge due to poor permeability of antigens through the skin barrier. To overcome this limitation ultradeformable lipid vesicles, the elastic liposomes, could be a better module for transcutaneous delivery of these proteinaceous antigens. In the present investigation Hepatitis B surface antigen (HBsAg)-loaded elastic liposomes were utilized as a mode for enhanced immunity against the antigen. Elastic liposomes were prepared by conventional rotary evaporation method and characterized for various parameters such as vesicles shape and surface morphology, size and size distribution, entrapment efficiency, elasticity, turbidity, stability and in vitro release pattern. Ex vivo cellular uptake and fluorescence studies were also conducted. In vivo studies were performed by measuring the immune response elicited by topically applied HBsAg-loaded elastic liposomes and compared to the intramuscularly administered alum-adsorbed HBsAg solution, topically applied plain HBsAg solution and physical mixture of HBsAg and elastic liposomes. Results indicate that transcutaneous immunization via elastic liposomes induces robust systemic and mucosal antibody response against HBsAg as compared to other formulations. The fluorescence microscopy results suggest prominent skin permeation and biodistribution, demonstrating efficient delivery of antigens to the immunocompetent Langerhans cells (LC) and lymphatics. The elastic liposomal formulation provides higher entrapment efficiency, enhanced penetration and effective immunoadjuvant property justifying its potential for improved vaccine delivery.

Transdermal delivery of a pineal hormone: melatonin via elastic liposomes

Melatonin (MT) is a good candidate for transdermal delivery considering its short biological half-life, low molecular weight and a variable oral absorption. The objective of this work was to develop a novel formulation of melatonin for its efficient transdermal delivery. Melatonin loaded elastic liposomal formulation was prepared, characterized and the effect of this developed formulation on the in vitro permeation of melatonin across human cadaver skin was investigated, using a locally fabricated Franz diffusion cell. Skin permeation potential of the developed formulation was assessed using confocal laser scanning microscopy (CLSM), which revealed an enhanced permeation of the formulation to the deeper layers of the skin (up to 180 microm) following channel like pathways. Skin permeation profile of melatonin through elastic liposomal formulations was observed and the investigations revealed an enhanced transdermal flux (51.2+/-2.21 microg/cm(2)/h), decreased lag time (1.1h) and an optimum permeability coefficient (15.06+/-0.52 cm/h) for melatonin. The obtained flux was nearly 5 and 12.3 times higher than conventional liposomal and plain drug solution, respectively (P<0.005). Our result suggests the feasibility of elastic liposomal system for transdermal delivery of melatonin thereby eliminating the limitations of long lag time and poor skin permeation associated with the drug.