Bioinspired Design and Oriented Synthesis of Immunogenic Site-Specifically Penicilloylated Peptides.

ß-Lactam antibiotics allergy is recognized as a public health concern. By covalently binding to serum proteins, penicillins are known to form immunogenic complexes. The latter are recognized and digested by antigen-presenting cells into drug-hapten peptides leading to the immunization of treated persons and IgE-mediated hypersensitivity reactions encompassing anaphylaxis. If type I allergic reactions to drugs are often unpredictable, they are known to be dependent on CD4+ T-cells. This fundamental study revisits the chemical basis of the benzylpenicillin (BP) allergy with the aim of identifying immunologically relevant biomimetic benzylpenicilloylated peptides through the analysis of BP-conjugated human serum albumin (BP-HSA) profile and the evaluation of the naïve CD4+ T-cell responses to candidate BP-HSA-derived peptides. The chemical structures of BP-HSA bioconjugates synthesized in vitro at both physiological and basic pH were investigated by mass spectrometry. From the ten most representative lysine residues grafted by BP-hapten, HSA-bioinspired 15-mer peptide sequences were designed and the potential T-cell epitope profile of each peptide was predicted using two complementary in silico approaches, i.e., HLA class II binding prediction tools from the Immune Epitope Database and Analysis Resource (IEDB) and computational alanine scanning mutagenesis. Twelve structurally diversified benzylpenicilloylated peptides (BP-Ps) were selected and synthesized with the aid of a flexible synthesis pathway using an original benzylpenicilloylated lysine monomer as common precursor. In order to corroborate their predicted "epitope" profile, the naïve CD4+ T-cell response specific to BP was evaluated through a coculture approach. To our knowledge, this study showed for the first time the ability of bioinspired peptides structurally stemming from BP-HSA to be recognized by naïve CD4+ T-cells thus identifying a pre-existing T-cell repertoire for penicillin molecules bound to proteins. It also established a promising model approach expandable to other most frequently used penicillin classes of antibiotics to reveal biomimetic drug-modified antigenic peptides relevant for qualitative and quantitative drug allergy studies.

New Lidocaine-Based Pharmaceutical Cocrystals: Preparation, Characterization, and Influence of the Racemic vs. Enantiopure Coformer on the Physico-Chemical Properties.

This study describes the preparation, characterization, and influence of the enantiopure vs. racemic coformer on the physico-chemical properties of a pharmaceutical cocrystal. For that purpose, two new 1:1 cocrystals, namely lidocaine:dl-menthol and lidocaine:d-menthol, were prepared. The menthol racemate-based cocrystal was evaluated by means of X-ray diffraction, infrared spectroscopy, Raman, thermal analysis, and solubility experiments. The results were exhaustively compared with the first menthol-based pharmaceutical cocrystal, i.e., lidocaine:l-menthol, discovered in our group 12 years ago. Furthermore, the stable lidocaine/dl-menthol phase diagram has been screened, thoroughly evaluated, and compared to the enantiopure phase diagram. Thus, it has been proven that the racemic vs. enantiopure coformer leads to increased solubility and improved dissolution of lidocaine due to the low stable form induced by menthol molecular disorder in the lidocaine:dl-menthol cocrystal. To date, the 1:1 lidocaine:dl-menthol cocrystal is the third menthol-based pharmaceutical cocrystal, after the 1:1 lidocaine:l-menthol and the 1:2 lopinavir:l-menthol cocrystals reported in 2010 and 2022, respectively. Overall, this study shows promising potential for designing new materials with both improved characteristics and functional properties in the fields of pharmaceutical sciences and crystal engineering.