Optical Detection of Degraded Therapeutic Proteins

Advancing precision cancer immunotherapy drug development, administration, and response prediction with AI-enabled Raman spectroscopy

Molecular characterization of tumors is essential to identify predictive biomarkers that inform treatment decisions and improve precision immunotherapy development and administration. However, challenges such as the heterogeneity of tumors and patient responses, limited efficacy of current biomarkers, and the predominant reliance on single-omics data, have hindered advances in accurately predicting treatment outcomes. Standard therapy generally applies a "one size fits all" approach, which not only provides ineffective or limited responses, but also an increased risk of off-target toxicities and acceleration of resistance mechanisms or adverse effects. As the development of emerging multi- and spatial-omics platforms continues to evolve, an effective tumor assessment platform providing utility in a clinical setting should i) enable high-throughput and robust screening in a variety of biological matrices, ii) provide in-depth information resolved with single to subcellular precision, and iii) improve accessibility in economical point-of-care settings. In this perspective, we explore the application of label-free Raman spectroscopy as a tumor profiling tool for precision immunotherapy. We examine how Raman spectroscopy's non-invasive, label-free approach can deepen our understanding of intricate inter- and intra-cellular interactions within the tumor-immune microenvironment. Furthermore, we discuss the analytical advances in Raman spectroscopy, highlighting its evolution to be utilized as a single "Raman-omics" approach. Lastly, we highlight the translational potential of Raman for its integration in clinical practice for safe and precise patient-centric immunotherapy.

Direct Quantification of Protein Antigens in Subunit Plague and Rickettsial Vaccine Preparations

The aim of the work was to put forward the methods for direct quantitative determination of the content of Yersinia pestis and Rickettsia raoultii protein antigens in preparations and various prototypes of subunit vaccines. Materials and methods. Y. pestis LcrV and Caf1 antigens enclosed in the substance of the molecular microencapsulated plague vaccine (MMPV) and separately, in microcrystals of amino acids co-precipitated with plague proteins were used as model antigens. R. raoultii Adr2, OmpB24, and YbgF antigens were adsorbed on the prototype substance of the rickettsia vaccine. The release of plague antigens from MMPV microcapsules was carried out through successive treatment of the latter with organic solvents, methylene chloride and methanol, respectively; the carrier microcrystals were dissolved in 0.1 M sodium citrate buffer at pH 6.0. The antigen content in the prototype substance of the rickettsial vaccine was determined by measuring the amount of proteins not bound to the alumogel. Quantitative parameters characterizing the content of antigens in the substances and prototypes of vaccine preparations were calculated by processing digital images of polyacrylamide gels obtained by electrophoresis of protein antigen fractions extracted from carriers. Results and discussion. Methods for direct extraction and subsequent quantitative analysis of Y. pestis LcrV and Caf1 antigens from subunit vaccine preparations based on amino acid microcrystals and polylactide microcapsules that do not cause protein degradation have been studied. A different nature of the binding of LcrV and Caf1 in the substances of microcrystals has been established, while the proportion of antigens released from microcrystals has been quantified only in case of their complete dissolution. It was found that at low concentrations of LcrV and Caf1 proteins extracted from microcrystals, it is necessary to concentrate the extracts with subsequent removal of salts for their reliable visualization. It has been confirmed that 10 μg of plague antigens and proteins of R. raoultii in a dose volume of 200 μl of suspension is sufficient for quantitative analysis using electrophoretic method. The prospects of other physicochemical methods alternative to direct extraction of antigens for evaluating the composition and quality of vaccine preparations are discussed.

Potential of Raman spectroscopy in facilitating pharmaceutical formulations development - An AI perspective

Drug development is time-consuming and inherently possesses a high failure rate. Pharmaceutical formulation development is the bridge that links a new chemical entity (NCE) to pre-clinical and clinical trials, and has a high impact on the efficacy and safety of the final drug product. Further, the time required for this process is escalating as formulation techniques are becoming more complicated due to the rising demands for drug products with better efficacy and patient compliance, as well as the inherent difficulties of addressing the unfavorable properties of NCEs such as low water solubility. The advent of artificial intelligence (AI) provides possibilities to accelerate the drug development process. In this review, we first examine applications of AI methods in different types of pharmaceutical formulations and formulation techniques. Moreover, as availability of data is the engine for the advancement of AI, we then suggest a potential way (i.e. applying Raman spectroscopy) for faster high-quality data gathering from formulations. Raman techniques have the capability of analyzing the composition and distribution of components and the physicochemical properties thereof within formulations, which are prominent factors governing drug dissolution profiles and subsequently bioavailability. Thus, useful information can be obtained bridging formulation development to the final product quality.

Raman Spectroscopy to Monitor Post-Translational Modifications and Degradation in Monoclonal Antibody Therapeutics

Monoclonal antibodies (mAbs) represent a rapidly expanding market for biotherapeutics. Structural changes in the mAb can lead to unwanted immunogenicity, reduced efficacy, and loss of material during production. The pharmaceutical sector requires new protein characterization tools that are fast, applicable in situ and to the manufacturing process. Raman has been highlighted as a technique to suit this application as it is information-rich, minimally invasive, insensitive to water background and requires little to no sample preparation. This study investigates the applicability of Raman to detect Post-Translational Modifications (PTMs) and degradation seen in mAbs. IgG4 molecules have been incubated under a range of conditions known to result in degradation of the therapeutic including varied pH, temperature, agitation, photo, and chemical stresses. Aggregation was measured using size-exclusion chromatography, and PTM levels were calculated using peptide mapping. By combining principal component analysis (PCA) with Raman spectroscopy and circular dichroism (CD) spectroscopy structural analysis we were able to separate proteins based on PTMs and degradation. Furthermore, by identifying key bands that lead to the PCA separation we could correlate spectral peaks to specific PTMs. In particular, we have identified a peak which exhibits a shift in samples with higher levels of Trp oxidation. Through separation of IgG4 aggregates, by size, we have shown a linear correlation between peak wavenumbers of specific functional groups and the amount of aggregate present. We therefore demonstrate the capability for Raman spectroscopy to be used as an analytical tool to measure degradation and PTMs in-line with therapeutic production.