Category Archives: Publications

Collagen, derived from various biological sources, is crucial in supporting a range of physiological processes and developmental pathways. However, concerns have been raised regarding the potential teratogenic effects of collagen. The zebrafish (Danio rerio) model has emerged as a premier vertebrate model for investigating the impact of biomaterials on vertebrate development, both under normal and pathological conditions. The present study sought to assess the acute toxicity, developmental toxicity, cardiotoxicity, and teratogenic toxicity of fish collagen extracted from Decapterus macarellus fish species on various developmental parameters. Acid-solubilized collagen was extracted from D. macarellus, and zebrafish embryos (<96 h) were subsequently exposed to varying collagen concentrations of 62.5 parts per million (ppm), 125 ppm, 250 ppm, 500 ppm, and 1000 ppm. Key developmental parameters, including survival rate, hatching rate, heart rate, and deviations in four apical points: embryo coagulation, lack of somite formation, non-detachment of the tail, and lack of heartbeat observations were recorded over a period of 0–96 h post-fertilization (hpf ). Positive and negative controls were parallelly carried out analysing the results statistically with pairwise Kruskal–Wallis test followed by a Dunn pairwise test.

The results indicated that the survival rate of zebrafish embryos ranged from 96.97±5.25 to 82.28±9.80%
at 96 hpf across all tested collagen concentrations. No significant differences were observed (P>0.05) compared to the negative control group or between the various treated concentrations. The hatching rate at 48 hpf and heart rates at 72 hpf and 96 hpf in the treated groups showed no significant variations compared to the negative control (P>0.05). Furthermore, no abnormal changes were recorded in the four apical points; embryo coagulation, lack of somite formation, non-detachment of the tail, and lack of heartbeat in embryos, treated with collagen. All the observed results cumulatively indicated the nontoxic effect of collagen from D. macarellus on zebrafish embryo development.

The results confirm the extracted from D. macarellus is nontoxic and causes no teratogenic effects in zebrafish embryo development. It further validates the potential of using collagen as a biocompatible material, where non-toxicity and developmental safety are paramount.

Published in: iForest

DOI: http://www.sisef.it/iforest/contents/?id=ifor4632-017

This study integrates NASA’s Global Ecosystem Dynamics Investigation (GEDI) spaceborne LiDAR data with multispectral satellite imagery to map the vegetation and assess spatial dynamics within the Sinharaja Forest Reserve (SFR), located in the southwestern Sri Lanka. Utilizing advanced remote sensing techniques, we delineated vegetation structure, vegetation density distribution, and canopy cover at high spatial resolutions. Eight distinct vegetation/land cover types were identified and an updated vegetation map was developed for SFR. The resulted map recorded an estimated overall accuracy of 90% (Kappa coefficient = 0.9) by the accuracy assessment. Comprehensive insights into forest composition and spatial dynamics were achieved with regard to canopy heights, plant area index and plant area volume density. Our results suggest that the integration of GEDI LiDAR and satellite imaging data offers a robust framework for characterizing tropical forest ecosystems, facilitating better understanding of their ecological processes, and informing conservation and management strategies.

Published in: Regional Studies in Marine Science

DOI: https://doi.org/10.1016/j.rsma.2025.104120

There is limited knowledge of the physical and chemical properties of the biofouling organisms in the coastal waters surrounding Sri Lanka. This study investigates the chemical diversity and environmental resilience of nine species of marine macrofouling organisms through secondary metabolite-induced effects on biofilm formation. The anti-settlement assay revealed that Schizoporella errata, Botrylloides violaceus, Callyspongia diffusa, Halichondria panicea and Acanthella cavernosa showed significant resistance to Escherichia coli settlement and biofilm formation within the first 12 h (OD600 < 0.1). Following gas chromatographic and mass spectrometry (GC-MS) analysis, antimicrobial compounds such as dodecanoic acid, methyl palmitate, β-caryophyllene, hentriacontane geraniol and β-asarone were detected in these species.

Published in: PLoS One

DOI: https://doi.org/10.1371/journal.pone.0337428

Phlebotomus argentipes sensu lato Annandale & Brunetti, 1908 is the primary vector of Leishmania donovani MON 37, the causative agent of cutaneous leishmaniasis (CL) in Sri Lanka. Effective vector control is essential for managing leishmaniasis. Although numerous taxonomic studies have been conducted on P. argentipes s.l., population genetics remains insufficiently explored. This study investigated the demographic history and population genetic structure of P. argentipes s.l. in Sri Lanka using sequence data obtained from the earlier investigation of two mitochondrial markers, Cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit 4 (ND4). For the genetic analysis, 159 individuals from five leishmaniasis endemic sites were examined. In addition to the individual analyses of COI and ND4 genes, a concatenated dataset combining both mitochondrial fragments was constructed to evaluate overall genetic structure and demographic history. The population structure and demographic history of P. argentipes s.l. were assessed using FST estimates, AMOVA, structure analysis, Mantel test, PCoA, Bayesian inference and coalescent analysis. The highest FST value was 0.0271, indicating low genetic differentiation, with over 98% variation occurring within populations. Mantel tests showed weak, non-significant correlations between genetic and geographic distance, indicating no evidence of isolation by distance, suggesting potential gene flow and no distinct clustering within the Sri Lankan P. argentipes s.l. population. Negative and significant neutrality statistics, together with unimodal mismatch distributions, support historical population expansion, further corroborated by Bayesian skyline plots indicating two distinct demographic events, an ancient expansion around 50,000 years ago (COI) and a more recent one approximately 10,000–13,000 years ago (ND4). Additionally, the mismatch distribution analyses revealed a multimodal expansion pattern at the Medirigiriya and Hambantota sites, which are hot spots for leishmaniasis in Sri Lanka. The present study demonstrates a demographic expansion and genetic homogeneity of P. argentipes s.l. populations in Sri Lanka, supporting the species’ ability to colonize new areas and possibly enhance leishmaniasis transmission. This connectivity may facilitate the spread of adaptive traits such as insecticide resistance, even in the absence of local selection pressure, posing a potential challenge for future vector control efforts in Sri Lanka.