Alzheimer's disease (AD), the most common neurodegenerative disorder, is pathologically defined by amyloid-β plaques and tau tangles. Current diagnostic tools like CSF analysis and PET imaging are invasive or costly, limiting routine use. This study proposes a novel, label-free approach using Fourier-transform infrared (FTIR) spectroscopy to identify disease-specific biochemical signatures in plasma-derived small extracellular vesicles (sEVs) from 30  AD patients and 20 age-matched controls. sEVs were validated by ultracentrifugation, TEM, nanoparticle tracking (mean size: 98.7 ± 12.4 nm in AD vs. 102.3 ± 14.1 nm in controls), and Western blot for CD9, CD81, and TSG101. FTIR analysis revealed significant alterations in AD sEVs: consistent increase in lipid peroxidation (based on 3015 cm−1, 1745 cm−1 bands), 19.8 % change in β-sheet content, and 22.4 % enhancement in phosphate vibrations (1072 cm−1). Key spectral ratios showed excellent diagnostic accuracy, with the lipid peroxidation index (AUC = 0.998) and protein disorder index (AUC = 0.978). This rapid, cost-effective, and non-invasive method enables simultaneous assessment of lipid, protein, and glycan changes in AD. With broader validation, FTIR-based profiling of plasma sEVs could offer a transformative tool for early AD diagnosis and monitoring.

Background

Parkinson's disease (PD) is a progressive neurodegenerative disorder lacking reliable, early-stage diagnostic biomarkers. This study utilizes Fourier Transform Infrared (FTIR) spectroscopy to identify biochemical alterations in plasma-derived small extracellular vesicles (PsEVs) from PD patients.

Methods

PsEVs were isolated and characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and immunoblotting for canonical markers (TSG101, CD63, and CD9). FTIR spectra were recorded in the mid-infrared region (900–3100 cm−1) to probe molecular signatures of lipids and proteins.

Results

Significant spectral differences were observed between PD and AM-C sEVs, in the lipid-associated regions- I2960/I2929 for CH₃/CH₂ asymmetric stretch (AUC = 0.991; Sn = 100%, Sp = 86.67%), I3040/I2929 for olefinic/saturated lipid ratios (AUC = 0.973; Sn = 96.67%, Sp = 86.67%), and protein-associated amide-I region, using Erik Goormaghtigh's MATLAB Kinetics and demonstrated a strong discriminatory power. Multivariate PCA and hierarchical clustering analyses also confirmed clear segregation.

Conclusion

FTIR revealed lipid-based spectral biomarkers in PsEVs, highlighting their potential for early diagnostic tools for PD screening and monitoring.

Small extracellular vesicles (sEVs) can provide information about the pathophysiology of the cells; therefore, sEVs have attracted considerable interest as possible diagnostic biomarkers. A key challenge lies in the necessity for simple and cost-effective sEV isolation methods to achieve high purity and yield suitable for research and clinical applications. We are introducing a comprehensive study on isolating sEVs using a novel cocktail strategy that integrates chemical precipitation and ultrafiltration with a two-step filtering process to ensure a highly pure and homogeneous population and further compared with PEG-based precipitation, ultra-centrifugation, and size-exclusion-chromatography columns. The isolated sEVs from each protocol are quantified for size and yield using nanoparticle tracking analysis, morphologically characterized through transmission electron microscopy, and validated by quantifying the expression profiles of sEV surface biomarkers. Furthermore, the study explores the applicability of our method for downstream multi-omics analyses. The results highlight the efficacy of the proposed protocol, demonstrating the ease and efficiency of isolating sEVs from different biofluids with minimal laboratory requirements and confirming the compatibility with multi-omics analyses. These findings position our method as particularly valuable for translational research, offering a promising avenue for advancing the study and application of sEVs in diagnostic and therapeutic research.

Contemporary research evidence has corroborated a gradual loss of central cholinergic neurons in Alzheimer's Disease (AD). This progressive deterioration leads to cognitive dysfunction and impaired motor activity, culminating in the brain cell's death in the disease. The approved drugs for AD treatment can only offer relief from symptoms without addressing the underlying pathological hallmarks of the disease. To address the limitations associated with rivastigmine (RIV), a marketed drug for AD, a series of tryptamine derivatives was designed, synthesized, and evaluated in various in-vitro and in-vivo AD models. Enzyme inhibition studies identified compounds 6d and 6e as the lead molecules with potent inhibitors against AChE (6d, IC50: 0.99 ± 0.009 nM and 6e IC50: 7.97 ± 0.016 nM and BChE (6d, IC50: 27.79 ± 0.21 nM and 6e, IC50: 0.79 ± 0.005 nM), compared to the marketed drug Riv (AChE, IC50: 6630 ± 0.76 nM, BChE IC50 = 91 ± 0.40 nM). The molecular docking and dynamics studies corroborated the enzyme inhibition studies. The PAMPA assay strongly suggested the BBB crossing ability of the lead molecules. Further, 6d and 6e demonstrated the capability to counteract oxidative stress and Aβ1-42 in various in-vitro studies. Compound 6e exhibited remarkable radical scavenging activity in the DPPH assay (IC50: 22.91 ± 1.73 μM) compared to rivastigmine (% radical scavenging activity: 3.71 ± 0.09 at 200 μM). Interestingly, 6d and 6e exhibited promising activity in the AD Drosophila model by protecting eye phenotypes from degeneration induced by Aβ1-42 toxicity and reduced mitochondrial and cellular oxidative stress in this model. Furthermore, upon oral administration, 6d and 6e could reverse scopolamine-induced amnesia by improving spatial and cognitive memory in mice at 0.3 and 0.5 mg/kg compared to rivastigmine at 3 mg/kg and were found to have potent ex-vivo anti-ChEs properties, which are correlated with the observed pro-cognitive effects in the Morris Water Maze, likely mediated through the inhibition of both cholinesterases. The expression of various neuroprotection markers, such as BDNF and TRKB, was significantly overexpressed compared to the disease control group.

Gastrointestinal neuroendocrine tumors (GI NETs) remain diagnostically challenging due to limitations of current methods. This study pioneers the application of Fourier-transform infrared (FTIR) spectroscopy for GI NET detection through plasma lipid profiling. Analyzing 22 patients and 8 controls, we identified specific biomarker ratios (I3015/I2929 and I3015/I1650) reflecting tumor-associated oxidative stress and membrane alterations. Multivariate analysis revealed excellent diagnostic accuracy (94–96.1% sensitivity, 100% specificity) superior to conventional biomarkers, with PCA showing clear group separation (96.5% variance). The FTIR approach demonstrated significant advantages: rapid analysis (< 5 min), minimal sample requirements (4 μL), and low cost, addressing critical clinical needs. Spectral changes correlated with known lipid metabolism dysregulation in NETs, particularly increased unsaturated fatty acids (3015 cm−1) and altered acyl chain packing (2929 cm−1). These findings establish FTIR as a practical, label-free alternative to invasive diagnostics, with potential for both early detection and treatment monitoring. The identified lipid signatures not only provide robust diagnostic markers but also suggest new therapeutic targets for NET management. This cost-effective technology could transform clinical practice by enabling routine screening and personalized treatment strategies. Future studies should validate these results in larger cohorts and explore correlations with tumor grade and treatment response.

Background: Alzheimer’s disease (AD) is a neurodegenerative disease characterized by Aβ plaques and neurofibrillary tangles. Chronic inflammation and synaptic dysfunction lead to disease progression and cognitive decline. Small extracellular vesicles (sEVs) are implicated in AD progression by facilitating the spread of pathological proteins and inflammatory cytokines. This study investigates synaptic dysfunction and neuroinflammation protein markers in plasma-derived sEVs (PsEVs), their association with Amyloid-β and tau pathologies, and their correlation with AD progression.

Methods: A total of 90 [AD = 35, mild cognitive impairment (MCI) = 25, and healthy age-matched controls (AMC) = 30] participants were recruited. PsEVs were isolated using a chemical precipitation method, and their morphology was characterized by transmission electron microscopy. Using nanoparticle tracking analysis, the size and concentration of PsEVs were determined. Antibody-based validation of PsEVs was done using CD63, CD81, TSG101, and L1CAM antibodies. Synaptic dysfunction and neuroinflammation were evaluated with synaptophysin, TNF-α, IL-1β, and GFAP antibodies. AD-specific markers, amyloid-β (1–42), and p-Tau were examined within PsEVs using Western blot and ELISA.

Results: Our findings reveal higher concentrations of PsEVs in AD and MCI compared to AMC (p < 0.0001). Amyloid-β (1–42) expression within PsEVs is significantly elevated in MCI and AD compared to AMC. We could also differentiate between the amyloid-β (1–42) expression in AD and MCI. Similarly, PsEVs-derived p-Tau exhibited elevated expression in MCI compared with AMC, which is further increased in AD. Synaptophysin exhibited downregulated expression in PsEVs from MCI to AD (p = 0.047) compared to AMC, whereas IL-1β, TNF-α, and GFAP showed increased expression in MCI and AD compared to AMC. The correlation between the neuropsychological tests and PsEVs-derived proteins (which included markers for synaptic integrity, neuroinflammation, and disease pathology) was also performed in our study. The increased number of PsEVs correlates with disease pathological markers, synaptic dysfunction, and neuroinflammation.

Conclusions: Elevated PsEVs, upregulated amyloid-β (1–42), and p-Tau expression show high diagnostic accuracy in AD. The downregulated synaptophysin expression and upregulated neuroinflammatory markers in AD and MCI patients suggest potential synaptic degeneration and neuroinflammation. These findings support the potential of PsEV-associated biomarkers for AD diagnosis and highlight synaptic dysfunction and neuroinflammation in disease progression.

The survival rate over a five-year period for rare pancreatic neuroendocrine tumors (PanNET) is notably lower compared to other neuroendocrine tumors due to late-stage detection, which is a consequence of the absence of suitable diagnostic markers; therefore, there exists a critical need for an early-stage biomarker-specific to PanNETs. This study introduces a novel approach, investigating the impact of small extracellular vesicles (sEV) in PanNET growth and metastasis. As proof of concept, this study shows a correlation between sEV concentration in controls and PanNET. Notably, higher sEV concentrations were observed in PanNETs than in controls (p < 0.0001) with a sensitivity of 100%. Further, apparent differences were observed in the sEV concentrations between controls and grades 1 PanNET (p = 0.005). The expression of sEV markers was confirmed using CD63, TSG101, CD9, Flotillin-1, and GAD65 antibodies. Additionally, the expression of cancer marker BIRC2/cIAP1 (p = 0.002) and autophagy marker Beclin-1 (p = 0.02) were observed in plasma-derived sEVs and PanNET tissue. This study represents the first to indicate the increased secretion of sEV in PanNET patients&apos; blood plasma, proposing potential function of sEV as a new biomarker for early-stage PanNET detection.

Alzheimer's disease (AD) is a neurodegenerative disorder marked by significant loss of central cholinergic neurons. This progressive deterioration leads to cognitive dysfunction and impaired motor activity, culminating in the brain cell's death at the later stages of the disease. The approved drugs for AD are limited to providing symptomatic relief for an initial period due to the multifaceted etiology of the disease. Several studies have demonstrated that rivastigmine (RIV) is a selectively potent inhibitor of butyrylcholinesterase and devoid of antioxidant, Aβ, and tau protein aggregation inhibition and anti-inflammatory properties. Therefore, to address these issues associated with RIV, novel rivastigmine-based molecules were rationally designed, synthesized, and evaluated in various in-vitro and in-vivo AD models. In in-vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition studies revealed that 3q & 6e as promising leads (AChE, IC50 1.72 ± 0.15, 0.91 ± 0.016 μM, BChE, IC50 6.69 ± 0.28 μM, 1.19 ± 0.026 μM, for 3q & 6e, respectively). The computational studies (molecular docking and dynamics) further corroborated the in-vitro studies. Further, 3q and 6e were found to be potent antioxidants in the DPPH assay (IC50 16.15 ± 1.05 & 15.17 ± 0.07 μM, for 3q & 6e, respectively). Interestingly, 3q, and 6e could effectively inhibit self-induced full-length tau and Aβ1-42 aggregation. Treatment with 3q & 6e inhibited microglial activation by attenuating ROS release and mitochondrial damage. Further, 3q & 6e also suppressed NLRP3 inflammasome and NF-κB expression levels in microglial cells and halted the release of pro-inflammatory cytokines in human microglial cells. Finally, 3q & 6e were found to be efficacious in reversing the scopolamine-induced memory impairment in the Morris water maze test. The expression of various neuroprotection markers, such as BDNF and TRKB, was significantly overexpressed compared to the disease control group.