Biology subjects

Ahmmed, R.

Publications and source records attributed to Ahmmed, R..

5 recordsLinked to original sources

bioRxiv2026

Mesoscopic Fluorescence Imaging of Light-Triggered Chemotherapeutic Release in Cancer Spheroid Models

Peritoneal micrometastases (micromets) remain a major barrier to durable cytoreduction in ovarian and other intra-abdominal cancers, because lesions can be difficult to visualize and are often resistant to systemic therapy. Liposomal doxorubicin (Dox) improves pharmacokinetics but can be limited by slow intratumoral release. Porphyrin-phospholipid (PoP) liposomes enable near-infrared light-triggered release of Dox (chemophototherapy (CPT)), creating an opportunity for intraoperative, fluorescence-guided treatment planning and monitoring. Here, we evaluate a laparoscopic fluorescence imaging platform for quantifying light-triggered drug delivery in 2D monolayers and 3D spheroid cluster models. Dox fluorescence increased linearly with administered LC-Dox-PoP concentration in both SCC2095sc and SKOV-3 cultures (R2 = 0.97-0.98 in 2D; R2 = 0.98 in spheroid clusters over 1-9 {micro}g/mL). Laparoscope-derived fluorescence measurements agreed with standard well-plate reader measurements (R2 = 0.89-0.96). Porphyrin fluorescence provided stronger, complementary contrast for localizing spheroid constructs and decreased after activation light exposure, consistent with photobleaching during triggered release. Together, these results support a quantitative imaging framework for fluorescence-guided monitoring of light-triggered liposomal drug release, with potential to inform individualized CPT dosimetry for peritoneal micrometastases. These findings in SCC2095sc (oral squamous cell carcinoma) additionally suggest relevance of fluorescence-guided CPT for head and neck/oral cancer, where localized post-resection adjuvant treatment may improve control of residual disease.

bioengineering↗

bioRxiv2026

Depth-Sensitive Optical Property Characterization Using Multi-Frequency Laparoscopic SFDI

Accurate knowledge of tissue absorption (a) and reduced scattering [Formula] parameters are required to plan and monitor laparoscopic chemophototherapy (CPT) in ovarian cancer, including light dosimetry and quantitative fluorescence mapping of porphyrin-phospholipid (PoP) photobleaching and light-triggered doxorubicin (Dox) release. We implemented a depth-sensitive, multi-frequency laparoscopic spatial frequency domain imaging (SFDI) framework to improve optical-property estimation in layered tissue. A DMD-based laparoscope imaged two-layer phantoms with controlled optical contrasts and superficial thicknesses. Spatial-frequency subsets associated with different penetration depths were independently fit to recover a and [Formula], and compared with a two-layer diffusion model. Recovered [Formula] values remained bounded by the known layer references and shifted monotonically toward the superficial value as spatial frequency and top-layer thickness increased, approaching a single-layer response at high frequency/thick layers. Quantitative model comparison showed {delta}-P1 variants outperformed the standard diffusion approximation, reducing RMSPE between modeled and measured [Formula] to 0.8-6.5% (silicone/silicone) and 1.6-8.3% (silicone/intralipid), whereas SDA errors reached [~]13.8% and 21.1%, respectively. This approach demonstrates multi-frequency laparoscopic SFDI as a practical initial step for depth-sensitive fluorescence correction for individualized CPT treatment planning and monitoring.

bioengineering↗

bioRxiv2025

Quantitative Fluorescence Imaging of Porphyrin Phospholipid Photobleaching and Light Activated Liposomal Doxorubicin Release Using Wide-field and Laparoscopic SFDI in an Ovarian Cancer Model

Chemophototherapy (CPT) is an emerging cancer treatment that leverages the synergistic effects of photodynamic therapy (PDT) and chemotherapy. This approach utilizes photosensitizers like Porphyrin Phospholipid (PoP) and Doxorubicin (Dox) to enable phototriggered drug release and targeted tumor destruction. In this study, we present the development and validation of a wide-field laparoscopic spatial frequency domain imaging (SFDI) system, designed to improve intraoperative quantitative fluorescence imaging and monitoring of PoP photobleaching, a PDT-driven effect for tumor destruction, and light-activated Dox release, which facilitates targeted chemotherapeutic drug delivery in an ovarian cancer model. Compared to previous flexible endoscopic imaging methods, our laparoscopic SFDI system offers enhanced spatial coverage, enabling accurate wide-field optical property quantification in minimally invasive surgical settings. Using this system, we performed quantitative fluorescence imaging in vivo to obtain absolute concentrations of PoP and Dox fluorescence, correcting for tissue absorption and scattering effects. This capability allows for precise assessment of PoP photobleaching and Dox release kinetics with improved spatial resolution. Fluorescence imaging revealed a significant reduction in PoP concentration in tumor regions post-illumination, demonstrating the PDT-mediated photobleaching effect and successful light-triggered drug release activation for chemo-induced tumor destruction. The ability to differentiate PoP and Dox fluorescence in a laparoscopic system underscores its potential for real-time intraoperative monitoring of CPT efficacy. These findings establish wide-field laparoscopic SFDI as a promising tool for guiding minimally invasive photodynamic therapy and targeted drug delivery in clinical settings.

bioengineering↗

bioRxiv2024

Optimization of citric acid production from sugarcane molasses using Aspergillus niger by submerged Fermentation

The potentiality of citric acid on economy is high because of its multi-purpose uses, particularly in the food and pharmaceutical industries. Bangladesh spent more than million US dollars to import citric acid mostly from India and China. Its consumption is increasing 3.5-4%, annually, indicating the need for better manufacturing alternatives. Globally, citric acid is primarily produced through microbial fermentation with Aspergillus niger. To support the massive scale of production of citrate, the manufacturing process must be eco-friendly which should be inexpensive and available raw materials for maintaining high yielding in a cost-effective manner. In Bangladesh prospective, the current study has undertaken to optimize citric acid production using one of the most abundant raw materials sugarcane molasses. Moreover, the aim of this study was to determine the optimum conditions to produce citric acid from sugarcane molasses using Aspergillus niger (F-81) by submerged fermentation. The amount of citric acid production was determined by Marier-Boulet colorimetric method. The optimization data suggested that 10% substrate (from processed cane molasses), 4% inoculum size of A. niger, and initial pH 6.0 allowed to produce around 25.8 g/L citric acid. Further study is warranted to assess the feasibility of citrate production in an industrial level as well as improvement of microbial strains is needed to further enhance citric acid production.

microbiology↗

bioRxiv2024

Study of Plasma Adiponectin Levels in Patients with Metabolic Syndrome and Therapeutic Indication in Bangladesh

BackgroundThe metabolic syndrome (Met-S) is a cluster of some interrelated common clinical disorders, including central obesity, dyslipidemia, hypertension, and glucose intolerance. Central obesity, accompanied by insulin resistance, is a key factor for the development of metabolic syndrome. Adiponectin is an adipose-specific plasma protein, secreted from adipocyte with anti-atherogenic and insulin-sensitizing activities. PurposeThis study aimed to investigate the relationship of plasma adiponectin levels with metabolic syndrome, related disorders and its drug repurposing through in silico approach. Materials and MethodsFor this study, 269 individuals were recruited with written consent. The participants were selected based on their full medical history, clinical examination, and laboratory reports. Anthropometric measurements as well as blood pressure was measured before sample collection. Fasting blood samples were collected for the estimation of lipid profile, blood glucose, and serum adiponectin levels. ResultsOur results show that the adiponectin levels in the subjects with Met-S were significantly lower than those of without Met-S (p <0.0001). Among the metabolic syndrome risk factors, adiponectin levels were associated with hypertriglyceridemia and reduced HDL-cholesterol (p<0.0001). Three drugs (Saquinavir, Candesartan and Glimepiride) were suggested to control the plasma adiponectin level in the subjects with Met-S. ConclusionsSince the plasma adiponectin levels are significantly lower in patients with Met-S, it might be used as diagnostic & prognostic marker for Met-S disorder and adiponectin targeted drugs might be minimize the Met-S of the subjects.

biochemistry↗