Active compounds of Crataegus nigra as components of albumin/tannin nanoparticles for targeted drug delivery in neurovascular protection

Background: The use of anti-inflammatory drugs for stroke and intracranial hemorrhage is limited by rapid renal clearance and toxicity. Human serum albumin (HSA) nanoparticles provide a biocompatible platform for drug delivery but require structural stabilization. Blueberry tannins non-covalently crosslink albumin, enhancing stability and antioxidant capacity. Crataegus nigra (black hawthorn) provides active polyamines, flavonoids, and organic acids with cardiovascular and antiplatelet properties. Objective: To evaluate albumin nanoparticles crosslinked with blueberry tannins and loaded with therapeutic agents (dexamethasone, allopurinol, and proline-rich peptide-1 (PRP-1)) and Crataegus nigra bioactives, assessing their stability, in silico receptor interactions, effects on platelet aggregation, and circulation time. Methods: Blueberry tannins (2.5 mg/mL) and human serum albumin (10 mg/mL) were co-assembled and loaded with dexamethasone (0.5 mg/mL), allopurinol (0.071 mg/mL), PRP-1 (1.0 mg/mL) and Crataegus nigra extract (3.0 mg/mL). Particle size and charge were measured by dynamic light scattering (DLS). Polyamines were identified by reversed-phase high-performance liquid chromatography (RP-HPLC). Platelet aggregation was evaluated under ADP dependent mechanism. AutoDock Vina was used for receptor docking. Nanoparticle circulation was monitored over 9 days in rats (Protocol NAS-IB-2024-0810). Results: Plain albumin nanoparticles displayed a particle size of 37.71 ± 0.96 nm and charge of -4.92 ± 0.93 mV. Tannin crosslinking increased particle size to 80.53 ± 1.76 nm and made the charge more negative (-18.72 ± 0.28 mV). Drug-loaded formulations showed negative charges (-13.29 ± 2.41 to -20.48 ± 0.11 mV) and bimodal size distributions (9.16 ± 0.28 nm and 92.02 ± 3.28 nm). RP-HPLC identified putrescine (0.016 ± 0.002 mg/g) as the main polyamine in the plant extract. Putrescine and the crude extract accelerated platelet aggregation (p = 0.01), whereas spermine and spermidine delayed aggregation (p < 0.03). Docking predicted strong binding to the P2X1 receptor (-6.41 to -7.09 kcal/mol). Plain nanoparticles were cleared within 9 days, while tannin-stabilized nanoparticles showed circulating retention ranging from 37.22% ± 3.24% to 53.45% ± 5.22% on day 9. Conclusion: Blueberry tannins and Crataegus nigra bioactives synergistically enhance albumin nanoparticle stability, bioactivity and biological half-life, providing a novel functional food-derived nanomedicine, with potential applications in acute neurovascular protection. Novelty of the Study: This study demonstrates a dual-acting nanomedical platform integrating blueberry tannin crosslinking for extended circulation with Crataegus nigra polyamines for platelet modulation, bridging functional food phytochemistry and neurovascular therapeutics. Keywords: albumin/tannin nanoparticles, Crataegus nigra, polyamines, platelets, aggregation, ADP.