Platelets are routinely stored enabling transfusions for a range of conditions. While the current platelet storage bags, composed of either polyvinylchloride or polyolefin, are well-established, the storage of platelets in these bags beyond 7 days reduces platelet viability below clinically usable levels. New materials and coatings that promote platelet respiration while not supporting platelet adhesion or activation have started to emerge, with the potential to enable platelet storage beyond 7 days. This review focuses on the literature describing currently used biomaterials for platelet storage and emerging materials that are showing promise for improving platelet storage.

Surface modification of biomaterials is a promising approach to control biofunctionality while retaining the bulk biomaterial properties. Perlecan is the major proteoglycan in the vascular basement membrane that supports low levels of platelet adhesion but not activation. Thus, perlecan is a promising bioactive for blood-contacting applications. This study furthers the mechanistic understanding of platelet interactions with perlecan by establishing that platelets utilize domains III and V of the core protein for adhesion. Polyvinyl chloride (PVC) is functionalized with recombinant human perlecan domain V (rDV) to explore the effect of the tethering method on proteoglycan orientation and bioactivity. Tethering of rDV to PVC is achieved via either physisorption or covalent attachment via plasma immersion ion implantation (PIII) treatment. Both methods of rDV tethering reduce platelet adhesion and activation compared to the pristine PVC, however, the mechanisms are unique for each tethering method. Physisorption of rDV on PVC orientates the molecule to hinder access to the integrin-binding region, which inhibits platelet adhesion. In contrast, PIII treatment orientates rDV to allow access to the integrin-binding region, which is rendered antiadhesive to platelets via the glycosaminoglycan (GAG) chain. These effects demonstrate the potential of rDV biofunctionalization to modulate platelet interactions for blood contacting applications.

Objective: Olanzapine (OZ) is a thioeno benzodiazepine class second-generation or atypical antipsychotic that selectively binds to central dopamine D2 and serotonin (5-HT2c) receptors used for the treatment of schizophrenia and bipolar disorder. The present paper is aimed at developing an optimized liposome-loaded OZ as an approach for brain targeting through the nasal route for effective therapeutic management of schizophrenia. Methods: The OZ liposomes were prepared by the thin-film hydration method. Various independent variable such as phospholipid, cholesterol and sonication time was optimized by using Design-Expert® Software to obtain the dependent variables of entrapment efficiency, vesicle size and zeta potential. The optimized formulation was predicted based on the response obtained by the point prediction method. Results: The entrapment efficiency of the formulation was range between 72.9 and 85.1 %. The average particle size of all the 15 experimental runs lies between the minimum and maximum values of the size 258.33 to 325.32 nm, respectively. The zeta potential ranges from-27.53 to-11.46 mV. The optimized formulation for characterized for its morphology by Transmission Electron Microscopy (TEM). In vitro release studies of OZ-loaded liposomal formulation was carried by dialysis sac method using pH 7.4 phosphate buffer (PBS) as a medium. The maximum release was found to be 98.43±1.2 % up to 24 h. The R2 zero-order kinetics and Korsmeyer-Peppas model was found to be 0.9919 and 0.9664, respectively. The zero-order shows the best-fit model with a highest R2 value exhibiting better correlation and the ‘n’ value was also found to be 0.85; indicating both diffusion-controlled and swelling-controlled drug release that is anomalous transport. Conclusion: The results, clearly states that the prepared formulations justify the parameters and OZ might be a suitable candidate to target the brain through nasal delivery.

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