Targeting tumor microenvironment with photodynamic nanomedicine.

Photodynamic therapy (PDT) is approved for the treatment of certain cancers and precancer lesions. While early Photosensitizers (PS) have found their way to the clinic, research in the last two decades has led to the development of third-generation PS, including photodynamic nanomedicine for improved tumor delivery and minimal systemic or phototoxicity. In terms of nanoparticle design for PDT, we are witnessing a shift from passive to active delivery for improved outcomes with reduced PS dosage. Tumor microenvironment (TME) comprises of a complex and dynamic landscape with myriad potential targets for photodynamic nanocarriers that are surface-modified with ligands. Herein, we review ways to improvise PDT by actively targeting nanoparticles (NPs) to intracellular organelles such as mitochondria or lysosomes and so forth, overcoming the limitations caused by PDT-induced hypoxia, disrupting the blood vascular networks in tumor tissues-vascular targeted PDT (VTP) and targeting immune cells for photoimmunotherapy. We propose that a synergistic outlook will help to address challenges such as deep-seated tumors, metastasis, or relapse and would lead to robust PDT response in patients.

Comparison of Tumor Penetration of Podophyllotoxin-Carboxymethylcellulose Conjugates with Various Chemical Compositions in Tumor Spheroid Culture and In Vivo Solid Tumor.

Polymer conjugation is an attractive approach for delivering insoluble and highly toxic drugs to tumors. However, most reports in the literature only disclose the optimal composition without emphasizing rational design or composition optimization to achieve maximized biological effects. In this study, we aimed to demonstrate that composition of a polymer conjugate would determine its physiochemical characteristics, tumor penetration, and, ultimately, the in vivo efficacy. We also aimed to examine whether the tumor spheroid model could generate comparable results with the in vivo tumor model in terms of tumor penetration and efficacy of the various polymer conjugates. We have designed a polymer conjugate delivery system for a chemotherapeutic drug podophyllotoxin (PPT) by covalently conjugating PPT and polyethylene glycol (PEG) with acetylated carboxymethyl cellulose to yield conjugates containing various amounts of PPT and PEG. Depending on the composition, these conjugates self-assembled into nanoparticles (NPs) with different physicochemical properties. Conjugates with an increased PPT content formed particles with an increased diameter. In the present study, we selected three conjugates representing compositions containing high, medium, and low drug content, and compared their particle formation, drug release kinetics, their ability to penetrate tumor spheroid and in vivo s.c. tumor, and finally their antitumor efficacy in spheroid culture and an in vivo s.c. tumor model. We found that the low drug content conjugate formed smaller NPs (20 nm) compared to the high drug content conjugates (30-120 nm), and displayed faster drug release kinetics (5%/day vs 1-3%/day), improved tumor penetration, and enhanced antitumor efficacy in both the spheroid model and s.c. tumor model. In particular, the low drug content conjugate preferentially accumulated in the hypovascular region within the tumor, inducing complete regression of s.c. tumors and the metastasis to the lungs. Our data indicate composition optimization is needed to select the optimal conjugate, and tumor spheroid culture is a robust screening tool to help select the optimal formulation.

Synthesis of a Gemcitabine Prodrug for Remote Loading into Liposomes and Improved Therapeutic Effect.

The chemotherapeutic gemcitabine was actively and stably loaded into lipid nanoparticles through the formation of a prodrug. Gemcitabine was chemically modified to increase the lipophilicity and introduce a weak base moiety for remote loading. Several derivatives were synthesized and screened for their potential to be good liposomal drug candidates for remote loading by studying their solubility, stability, cytotoxicity, and loading efficiency. Two morpholino derivatives of GEM (22 and 23) were chosen as the preferred prodrugs for this purpose as they possessed the best loading efficiencies (100% for drug-to-lipid ratio of 0.36 w/w). This is a considerable improvement over a passive loading strategy where typical loading efficiencies are on the order of ∼10-20% for a drug-to-lipid ratio of ∼0.01. Liposomes loaded with these two prodrugs were studied in an s.c. tumor model in vivo and showed improved therapeutic effect over free GEM (∼2-fold) and saline control (8- to 10-fold). This work demonstrates how chemical modification of a known hydrophilic drug can lead to improved loading, stability, and drug delivery in vivo.

A Simple and Improved Active Loading Method to Efficiently Encapsulate Staurosporine into Lipid-Based Nanoparticles for Enhanced Therapy of Multidrug Resistant Cancer.

PURPOSE: This study was aimed at developing a new active loading method to stably encapsulate staurosporine (STS), a water insoluble drug, into lipid-based nanoparticles (LNPs) for drug targeting to tumors. METHODS: A limited amount of DMSO was included during the active loading process to prevent precipitation and facilitate the loading of insoluble STS into the aqueous core of a LNP. The drug loading kinetics under various conditions was studied and the STS-LNPs were characterized by size, drug-to-lipid ratio, drug release kinetics and in vitro potency. The antitumor efficacy of the STS-LNPs was compared with free STS in a mouse model. RESULTS: The drug loading efficiency reached 100% within 15 min of incubation at a drug-to-lipid ratio of 0.31 (mol) via an ammonium gradient. STS formed nano-aggregates inside the aqueous core of the LNPs and was stably retained upon storage and in the presence of serum. A 3-fold higher dose of the STS-LNPs could be tolerated by BALB/c mice compared with free STS, leading to nearly complete growth inhibition of a multidrug resistant breast tumor, while free STS only exhibited moderate activity. CONCLUSION: This simple and efficient drug loading method produced a stable LNP formulation for STS that was effective for cancer treatment.

Carboxymethylcellulose-based and docetaxel-loaded nanoparticles circumvent P-glycoprotein-mediated multidrug resistance.

Taxanes are a class of anticancer agents with a broad spectrum and have been widely used to treat a variety of cancer. However, its long-term use has been hampered by accumulating toxicity and development of drug resistance. The most extensively reported mechanism of resistance is the overexpression of P-glycoprotein (Pgp). We have developed a PEGylated carboxymethylcellulose conjugate of docetaxel (Cellax), which condenses into ∼120 nm nanoparticles. Here we demonstrated that Cellax therapy did not upregulate Pgp expression in MDA-MB-231 and EMT-6 breast tumor cells, whereas a significant increase in Pgp expression was measured with native docetaxel (DTX) treatment. Treatment with DTX led to 4-7-fold higher Pgp mRNA expression and 2-fold higher Pgp protein expression compared with Cellax treatment in the in vitro and in vivo system, respectively. Cellax also exhibited significantly increased efficacy compared with that of DTX in a taxane-resistant breast tumor model. Against the highly Pgp expressing EMT6/AR1 cells, Cellax exhibited a 6.5 times lower IC50 compared with that of native DTX, and in the in vivo model, Cellax exhibited 90% tumor growth inhibition, while native DTX had no significant antitumor activity.

Lizard Wears Shades. A Spectacled Sphenomorphus (Squamata: Scincidae), from the Sacred Forests of Mawphlang, Meghalaya, North-east India.

A new species of lygosomatine scincid lizard is described from the sacred forests of Mawphlang, in Meghalaya, northeastern India. Sphenomorphus apalpebratus sp. nov. possesses a spectacle or brille, an unusual feature within the Scincidae, and a first for the paraphyletic genus Sphenomorphus. The new species is compared with other members of the genus to which it is here assigned, as well as to members of the lygosomatine genera Lipinia and Scincella from mainland India, the Andaman and Nicobar Islands, and southeast Asia, to which it also bears resemblance. The new taxon is diagnosable in exhibiting the following combination of characters: small body size (SVL to 42.0 mm); moveable eyelids absent; auricular opening scaleless, situated in a shallow depression; dorsal scales show a line of demarcation along posterior edge of ventral pes; midbody scale rows 27-28; longitudinal scale rows between parietals and base of tail 62-64; lamellae under toe IV 8-9; supraoculars five; supralabials 5-6; infralabials 4-5; subcaudals 92; and dorsum golden brown, except at dorsal margin of lateral line, which is lighter, with four faintly spotted lines, two along each side of vertebral row of scales, that extend to tail base. The new species differs from its congeners in the lack of moveable eyelids, a character shared with several distantly related scincid genera.

A long-lost relic from the Eastern Ghats: Morphology, distribution and habitat of Sepsophis punctatus Beddome, 1870 (Squamata: Scincidae).

Sepsophis punctatus Beddome 1870, the only species of a monotypic genus, was described based on a single specimen from the Eastern Ghats of India. We rediscovered the species based on specimens from Odisha and Andhra Pradesh state, India, after a gap of 137 years, including four specimens from close to the type locality. The holotype was studied in detail, and we present additional morphological characters of the species with details on natural history, habitat and diet. The morphological characters of the holotype along with two additional specimens collected by Beddome are compared with the specimens collected by us. We also briefly discuss the distribution of other members of the subfamily Scincinae and their evolutionary affinities.

Chitosan, chondroitin sulfate, and hyaluronic acid based in-situ forming scaffold for efficient cell grafting.

Current cell grafting techniques are majorly dependent on seeding cells on a pre-formed scaffold. However, cells grow in a 2-dimensional (2D) space in such constructs, not mimicking the tissue's 3-dimensional (3D) architecture. The present study evaluated a unique poly-electrolyte complexation (PEC) based strategy for the 3D engraftment of cells in a porous polymeric scaffold. The scaffold was synthesized using a positively charged polysaccharide chitosan (CH) and negatively charged glycosaminoglycans chondroitin sulfate (CS) and hyaluronic acid (HA). Two different scaffolds were synthesized, one using CH and CS [CH-CS] and another using CH and CS + HA [CH-(CS-HA)]. The physicochemical characterization of both the PECs confirmed electrostatic interactions, leading to a porous and viscoelastic PEC formation. Fibroblast cells were grafted and seeded in both scaffolds to evaluate the effect of different scaffold compositions and the difference between seeded and grafted cells. Imaging studies confirmed that grafting of the fibroblast cells supports cellular proliferation. The qPCR studies demonstrated increased expression of functional markers TGF-ß, α-SMA, collagen-I, and fibronectin in the CH-(CS-HA) grafted cells. In summary, it was demonstrated that an in-situ forming PEC of CH, CS, and HA had good physicochemical properties for cell grafting and supported grafted cells with improved function.

Exploring temozolomide encapsulated PEGylated liposomes and lyotropic liquid crystals for effective treatment of glioblastoma: in-vitro, cell line, and pharmacokinetic studies.

Temozolomide (TMZ) is one of the best choices for treating glioblastoma. However, due to the short plasma half-life, only 20-30 % brain bioavailability can be achieved using traditional formulations. In the present study, PEGylated liposomes and lyotropic liquid crystals (LLCs) were developed and investigated to prolong the plasma circulation time of TMZ. Industrially feasible membrane extrusion and modified hot melt emulsification techniques were utilized during the formulation. Liposomes and LLCs in the particle size range of 80-120 nm were obtained with up to 50 % entrapment efficiency. The nanocarriers were found to show a prolonged release of up to 72 h. The cytotoxicity studies in glioblastoma cell lines revealed a âˆ¼1.6-fold increased cytotoxicity compared to free TMZ. PEGylated liposomes and PEGylated LLCs were found to show a 3.47 and 3.18-fold less cell uptake in macrophage cell lines than uncoated liposomes and LLCs, respectively. A 1.25 and 2-fold increase in the plasma t1/2 was observed with PEGylated liposomes and PEGylated LLCs, respectively, compared to the TMZ when administered intravenously. Extending plasma circulation time of TMZ led to significant increase in brain bioavailability. Overall, the observed improved pharmacokinetics and biodistribution of TMZ revealed the potential of these PEGylated nanocarriers in the efficient treatment of glioblastoma.

Apremilast loaded lyotropic liquid crystalline nanoparticles embedded hydrogel for improved permeation and skin retention: An effective approach for psoriasis treatment.

The present work aimed to prepare and evaluate Apremilast loaded lyotropic liquid crystalline nanoparticles (LCNPs) formulation for skin delivery to enhance the efficacy with reduced adverse effects of the oral therapy in psoriasis treatment. The LCNPs were prepared using the emulsification using a high shear homogenizer for size reduction and optimized with Box Behnken design to achieve desired particle size and entrapment efficiency. The selected LCNPs formulation was evaluated for in-vitro release, in-vitro psoriasis efficacy, skin retention, dermatokinetic, in-vivo skin retention, and skin irritation study. The selected formulation exhibited 173.25 ± 2.192 nm (polydispersity 0.273 ± 0.008) particle size and 75.028 ± 0.235% entrapment efficiency. The in-vitro drug release showed the prolonged-release for 18 h. The ex-vivo studies revealed that LCNPs formulation exhibited drug retention up to 3.2 and 11.9-fold higher, in stratum corneum and viable epidermis compared to conventional gel preparation. In-vitro cell line studies performed on immortal keratinocyte cells (HaCaT cells) demonstrated non-toxicity of selected excipients used in designed LCNPs. The dermatokinetic study revealed the AUC0-24 of the LCNPs loaded gel was 8.4 fold higher in epidermis and 2.06 fold in dermis, respectively compared to plain gel. Further, in-vivo animal studies showed enhanced skin permeation and retention of Apremilast compared to conventional gel.

Overcoming drug resistance with a docetaxel and disulfiram loaded pH-sensitive nanoparticle.

Previous studies have demonstrated that breast cancer cells deploy a myriad array of strategies to thwart the activity of anticancer drugs like docetaxel (DTX), including acquired drug resistance due to overexpression of drug-efflux pumps like P-glycoprotein (P-gp) and innate drug resistance by cancer stem cells (CSCs). As disulfiram (DSF) can inhibit both P-gp and CSCs, we hypothesized that co-treatment of DTX and DSF could sensitize the drug-resistant breast cancer cells. To deliver a fixed dose ratio of DTX and DSF targeted to the tumor, a tumor extracellular pH-responsive nanoparticle (NP) was developed using a histidine-conjugated star-shaped PLGA with TPGS surface decoration ([DD]NpH-T). By releasing the encapsulated drugs in the tumor microenvironment, pH-sensitive NPs can overcome the tumor stroma-based resistance against nanomedicines. In in-vitro studies, [DD]NpH-T exhibited increased drug release at pH 6.8, improved penetration in a 3D tumor spheroid, reduced serum protein adsorption, and enhanced cytotoxic efficacy against both innate and acquired DTX-resistant breast cancer cells. In in-vivo studies, a significant increase in plasma AUC and tumor drug delivery was observed with [DD]NpH-T, which resulted in an enhanced in-vivo anti-tumor efficacy against a mouse orthotopic breast cancer, with a significantly increased intratumoral ROS and apoptosis, while decreasing P-gp expression and prevention of lung metastasis. Altogether, the current study demonstrated that the DTX and DSF combination could effectively target multiple drug-resistance pathways in-vitro, and the in-vivo delivery of this drug combination using TPGS-decorated pH-sensitive NPs could increase tumor accumulation, resulting in improved anti-tumor efficacy.

Breaking the niche: multidimensional nanotherapeutics for tumor microenvironment modulation.

Most of the current antitumor therapeutics were developed targeting the cancer cells only. Unfortunately, in the majority of tumors, this single-dimensional therapy is found to be ineffective. Advanced research has shown that cancer is a multicellular disorder. The tumor microenvironment (TME), which is made by a complex network of the bulk tumor cells and other supporting cells, plays a crucial role in tumor progression. Understanding the importance of the TME in tumor growth, different treatment modalities have been developed targeting these supporting cells. Recent clinical results suggest that simultaneously targeting multiple components of the tumor ecosystem with drug combinations can be highly effective. This type of "multidimensional" therapy has a high potential for cancer treatment. However, tumor-specific delivery of such multi-drug combinations remains a challenge. Nanomedicine could be utilized for the tumor-targeted delivery of such multidimensional therapeutics. In this review, we first give a brief overview of the major components of TME. We then highlight the latest developments in nanoparticle-based combination therapies, where one drug targets cancer cells and other drug targets tumor-supporting components in the TME for a synergistic effect. We include the latest preclinical and clinical studies and discuss innovative nanoparticle-mediated targeting strategies.

Rational Molecular Designing of Aggregation-Enhanced Emission (AEE) Active Red-Emitting Iridium(III) Complexes: Effect of Lipophilicity and Nanoparticle Encapsulation on Photodynamic Therapy Efficacy.

Two "aggregation-enhanced emission" (AEE) active cyclometalated phosphorescent iridium(III) complexes, SM2 and SM4, were synthesized to evaluate the influence of lipophilicity on photodynamic therapy efficacy. Compared to SM2, SM4 had a higher logP due to the presence of naphthyl groups. As observed by confocal microscopy, this increased lipophilicity of SM4 significantly enhanced its cellular uptake in breast cancer cells. Both the molecules were found to be noncytotoxic under nonirradiating conditions. However, with light irradiation, SM4 exhibited significant cytotoxicity at a 500 nM dose, whereas SM2 remained noncytotoxic, signifying the influence of lipophilicity on cellular internalization and cytotoxicity. Mechanistically, light-irradiated SM4-treated cancer cells exhibited a significant increase in the intracellular reactive oxygen species (ROS) level. Neutralizing ROS with N-acetylcysteine (NAC) pretreatment partly abolished the cytotoxic ability, indicating ROS as one of the major effectors of cell cytotoxicity. Two nanoparticle (NP) formulations of SM4 were developed to improve the intracellular delivery: a PLGA-based NP and a Soluplus-based micelle. Interestingly, PLGA and Soluplus NP formulations exhibited a 10- and 22-fold increased emission intensity, respectively, compared to SM4. There was also an increase in the excited-state lifetime. Additionally, the Soluplus-based micelles encapsulating SM4 exhibited enhanced cellular uptake and increased cytotoxicity compared to the PLGA NPs encapsulating SM4. Altogether, the current study indicates the importance of rational molecular designing and the significance of a proper delivery vector for improving photodynamic therapy efficacy.

Phylogeny of the Asian Eutropis (Squamata: Scincidae) reveals an 'into India' endemic Indian radiation.

Recent generic rearrangement of the circumtropical distributed skink genus 'Mabuya' has raised a lot of debate. According to this molecular phylogeny based rearrangement, the tropical Asian members of this genus have been assigned to Eutropis. However, in these studies the Asian members of 'Mabuya' were largely sampled from Southeast (SE) Asia with very few species from Indian subcontinent. To test the validity of this assignment and to determine the evolutionary origin of Indian members of this group we sequenced one nuclear and two mitochondrial genes from most of the species from the Indian subregion. The nuclear and mitochondrial trees generated from these sequences confirmed the monophyly of the tropical Asian Eutropis. Furthermore, in the tree based on the combined mitochondrial and nuclear dataset an endemic Indian radiation was revealed that was nested within a larger Asian clade. Results of dispersal-vicariance analysis and molecular dating suggested an initial dispersal of Eutropis from SE Asia into India around 5.5-17 million years ago, giving rise to the extant members of the endemic Indian radiation. This initial dispersal was followed by two back dispersals from India into SE Asia. We also discuss the relationships within the endemic Indian radiation and its taxonomic implications.

Anticancer and immunostimulatory activity by conjugate of paclitaxel and non-toxic derivative of LPS for combined chemo-immunotherapy.

PURPOSE: Cancer is a multifactorial syndrome; hence, multidimensional therapy with a chemo-immunotherapeutic conjugate could be more effective in curing the disease. METHODS: We used SP-LPS, a bio-polymer having potent immunostimulatory activity, for conjugation with paclitaxel to make a chemo-immunotherapeutic conjugate. Its physicochemical characterization was done by HPLC, NMR and IR spectra. Stability was measured at different pH, temperature and in tissue homogenates. Chemotherapeutic and immunostimulatory activity was evaluated in vitro and also in tumor microenvironment. RESULTS: The conjugate self assembled into nanoparticulate structure, probably due to micelle formation. Stability was pH and temperature dependent. The conjugate exhibited chemotherapeutic and immunotherapeutic activity in vitro. In vivo antitumor activity was significantly higher and a higher percentage of activated immune cells were found in the tumor microenvironment of the conjugate-treated mice as compared to Taxol®-treated group. CONCLUSIONS: This conjugate is a potential chemo-immunotherapeutic compound for the treatment of cancer with advantages over present day chemotherapy with Taxol in terms of higher anticancer activity, less toxicity and ease of delivery.

pH-Responsive Nanoparticles for Multidimensional Combined Chemo-Immunotherapy of Cancer.

Current research has demonstrated that tumor development and progression are dependent on a multi-cellular interactome, which forms the tumor microenvironment. Multiple components of this multi-cellular ecosystem need to be targeted simultaneously for successful cancer therapy. The objective of this study was to develop a multidimensional combined chemo-immunotherapeutic modality for effective breast cancer treatment. TLR 7/8 agonist resiquimod was identified as a potent macrophage stimulant in an initial screening. To deliver paclitaxel as a chemotherapeutic drug and resiquimod as an immune activator in a tumor-targeted fashion, two different pH-sensitive nanoparticles were synthesized using two different polymers, a linear PLGA and a multi-arm, star-shaped PLGA. The star-PLGA pH-responsive nanoparticles exhibited improved pH-dependent drug release and increased penetration in a complex breast cancer spheroid model (breast cancer cell + macrophage cell). Treatment with paclitaxel and resiquimod encapsulated in the pH-responsive nanoparticles resulted in increased cancer cell death and macrophage activation, as tested in an in-vitro breast cancer spheroid model. Altogether, the current study suggests that the paclitaxel and resiquimod combination has potent chemo-immunotherapeutic activity, and delivery using a pH-sensitive nanoparticle further improves its efficacy.

Dual antibacterial and anti-inflammatory efficacy of a chitosan-chondroitin sulfate-based in-situ forming wound dressing.

None of the currently available wound dressings exhibit combined antibacterial and anti-inflammatory activity. Using polyelectrolyte complexation (PEC) between a cationic polysaccharide chitosan (CH) and an anionic glycosaminoglycan chondroitin sulfate (CS), we have developed a unique in-situ forming scaffold (CH-CS PEC), which develops at the wound site itself to influence the function of the wound bed cells. The current study demonstrated that CH-CS PEC could induce bacterial cell death through membrane pore formation and increased ROS production. Moreover, possibly due to its unique material properties including medium-soft viscoelasticity, porosity, and surface composition, CH-CS PEC could modulate macrophage function, increasing their phagocytic ability with low TNF-α and high IL-10 production. Faster wound closure and decreased CFU count was observed in an in-vivo infected wound model, with reduced NF-κB and increased VE-cadherin expression, indicating reduced inflammation and enhanced angiogenesis. In summary, this study exhibited that CH-CS PEC has substantial antibacterial and immunomodulatory properties.

Design and dermatokinetic evaluation of Apremilast loaded nanostructured lipid carriers embedded gel for topical delivery: A potential approach for improved permeation and prolong skin deposition.

The present study aimed to develop Apremilast loaded nanostructured lipid carriers (NLCs) for topical delivery to overcome the limitations of oral therapy and increase the efficacy. Apremilast loaded NLCs were prepared by hot emulsification technique. The developed formulation was optimized by Box Behnken design and characterized for size, entrapment efficiency, and zeta potential. The selected formulation was investigated for in-vitro release, ex-vivo skin retention, dermatokinetic, psoriasis efficacy, in-vivo skin retention and skin irritation study. The NLCs characterization results showed its spherical shape with the particle size of 157.91 ± 1.267 nm (0.165 ± 0.017 PDI). The entrapment efficiency and zeta potential were found to be 69.144 ± 0.278% and -16.75 ± 1.40 mV, respectively. The in-vitro release study revealed a controlled release of Apremilast from NLCs up to 24 h. The ex-vivo study showed 3-fold enhanced skin retention compared to conventional gel preparation. The formulation depicted improved psoriasis efficacy indicating reduced TNF-α mRNA expression. The cytotoxicity and skin irritation study revealed the prepared formulation has no toxicity or irritation. The study depicts the NLCs loaded Apremilast can be explored for the topical delivery for treatment of psoriasis with improved skin retention and efficacy.

Development of an in-situ forming, self-healing scaffold for dermal wound healing: in-vitro and in-vivo studies.

The importance of the extra-cellular matrix (ECM) for wound healing has been extensively researched. Understanding its importance, multiple ECM mimetic scaffolds have been developed. However, the majority of such scaffolds are prefabricated. Due to their stiffness, prefabricated scaffolds cannot come into direct contact with the basal skin cells at the wound bed, limiting their efficacy. We have developed a unique wound dressing, using chitosan (CH) and chondroitin sulfate (CS), that can form a porous scaffold (CH-CS PEC) in-situ, at the wound site, by simple mixing of the polymer solutions. As CH is positively and CS is negatively charged, mixing these two polymer solutions would lead to electrostatic cross-linking between the polymers, converting them to a porous, viscoelastic scaffold. Owing to the in-situ formation, the scaffold can come in direct contact with the cells at the wound bed, supporting their proliferation and biofunction. In the present study, we confirmed the cross-linked scaffold formation by solid-state NMR, XRD, and TGA analysis. We have demonstrated that the scaffold had a high viscoelastic property, with self-healing capability. Both keratinocyte and fibroblast cells exhibited significantly increased migration and functional markers expression when grown on this scaffold. In the rat skin-excisional wound model, treatment with the in-situ forming CH-CS PEC exhibited enhanced wound healing efficacy. Altogether, this study demonstrated that mixing CH and CS solutions lead to the spontaneous formation of a highly viscoelastic, porous scaffold, which can support epidermal and dermal cell proliferation and bio-function, with an enhanced in-vivo wound healing efficacy.

A new species of Asian gracile skink (Scincidae: Lygosominae: emSubdoluseps/em) from the rain-shadow belts of Nilgiri hills, Western Ghats, India.

We describe a new species of Asian gracile skink from the dry leeward slopes of the Nilgiri hills, Tamil Nadu state, India which forms a part of the eastern, rain shadow escarpment of the Western Ghats in peninsular India. The new species, Subdoluseps nilgiriensis sp. nov., is characterized by: slender, small-sized body (47-67 mm); sandy brown above, with each scale tipped with black; a thick black lateral band from snout to tail; a distinct white labial streak; dirty white venter, with throat having mild black striations; 28-29 midbody scale rows; 71-74 mid ventral scales; 66-69 paravertebral scales. The new species is described based on external morphological characters, genetic data and geographical isolation. Based on two mitochondrial DNA genes, we show that the new species shares a sister relationship with Subdoluseps pruthi (Sharma, 1977) which is found in parts of the Eastern Ghats in peninsular India. The discovery of this new population raises two novel scenarios. Firstly, it renders the genus Subdoluseps evolutionarily polyphyletic with respect to the Indian species included in this genus. Secondly, it falsifies the notion that S. pruthi group skinks are restricted to the Eastern Ghats. Our results further indicate that the dry zone of peninsular India has unrealized skink diversity that needs to be further explored.