Mechanism of Hydrogen-Bonded Complex Formation between Ibuprofen and Nanocrystalline Hydroxyapatite.

Nanocrystalline hydroxyapatite (nanoHA) is the main hard component of bone and has the potential to be used to promote osseointegration of implants and to treat bone defects. Here, using active pharmaceutical ingredients (APIs) such as ibuprofen, we report on the prospects of combining nanoHA with biologically active compounds to improve the clinical performance of these treatments. In this study, we designed and investigated the possibility of API attachment to the surface of nanoHA crystals via the formation of a hydrogen-bonded complex. The mechanistic studies of an ibuprofen/nanoHA complex formation have been performed using a holistic approach encompassing spectroscopic (Fourier transform infrared (FTIR) and Raman) and X-ray diffraction techniques, as well as quantum chemistry calculations, while comparing the behavior of the ibuprofen/nanoHA complex with that of a physical mixture of the two components. Whereas ibuprofen exists in dimeric form both in solid and liquid state, our study showed that the formation of the ibuprofen/nanoHA complex most likely occurs via the dissociation of the ibuprofen dimer into monomeric species promoted by ethanol, with subsequent attachment of a monomer to the HA surface. An adsorption mode for this process is proposed; this includes hydrogen bonding of the hydroxyl group of ibuprofen to the hydroxyl group of the apatite, together with the interaction of the ibuprofen carbonyl group to an HA Ca center. Overall, this mechanistic study provides new insights into the molecular interactions between APIs and the surfaces of bioactive inorganic solids and sheds light on the relationship between the noncovalent bonding and drug release properties

Administration of BNT162b2 mRNA COVID-19 vaccine to subjects with various allergic backgrounds

BackgroundThe mRNA-based COVID-19 vaccine was introduced to the general public in December 2020. Shortly thereafter, safety concerns were raised due to the reporting of allergic reactions. Allergy-related disorders were suspected to be significant risk factors and the excipient polyethylene glycol was suggested to be a robust allergen.MethodsThis is a retrospective study analysis. Subjects with putative risk factors for severe allergic reactions to the Pfizer-BioNTech BNT162b2 vaccine were referred for vaccination under observation at the Unit of Allergy and Clinical Immunology. Data was collected for each subject, including demographic details, medical history and previous reactions to any allergen. When appropriate, skin tests were done prior to vaccination.ResultsA total of 346 subjects received 623 vaccine doses under observation. The study included patients with various allergy-related disorders (n=290) and those with allergy to a previous COVID-19 vaccine dose (n=56). Both groups showed female predominance (78% and 88%, p=NS). Patients without reactions to previous doses reported more drug allergy (80% vs. 39%, p<0.001) and previous anaphylaxis (64% vs. 14%, p<0.001). There was no difference in sensitivity to other allergens, including polyethylene glycol. Under observation, mild allergic reactions were noted in 13 individuals characterized by female gender (100%), a history of anaphylaxis (69%) and drug allergy (62%). In 7 subjects, allergy was treated with antihistamines while others recovered spontaneously.ConclusionOur study demonstrates that vaccination under specialist-supervision is a powerful tool for reducing over-diagnosis of systemic reactions and for rapid and reliable collection of vaccine safety data

Strong, Light, Multifunctional Fibers of Carbon Nanotubes with Ultrahigh Conductivity

Broader applications of carbon nanotubes to real-world problems have largely gone unfulfilled because of difficult material synthesis and laborious processing. We report high-performance multifunctional carbon nanotube (CNT) fibers that combine the specific strength, stiffness, and thermal conductivity of carbon fibers with the specific electrical conductivity of metals. These fibers consist of bulk-grown CNTs and are produced by high-throughput wet spinning, the same process used to produce high-performance industrial fibers. These scalable CNT fibers are positioned for high-value applications, such as aerospace electronics and field emission, and can evolve into engineered materials with broad long-term impact, from consumer electronics to long-range power transmission