Enhancing cell and gene therapy manufacture through the application of advanced fluorescent optical sensors (Review)

Abstract

Cell and gene therapies (CGTs) are examples of future therapeutics that can be used to cure or alleviate the symptoms of disease, by repairing damaged tissue or reprogramming defective genetic information. However, despite the recent advancements in clinical trial outcomes, the path to wide-scale adoption of CGTs remains challenging, such that the emergence of a “blockbuster” therapy has so far proved elusive. Manufacturing solutions for these therapies require the application of scalable and replicable cell manufacturing techniques, which differ markedly from the existing pharmaceutical incumbent. Attempts to adopt this pharmaceutical model for CGT manufacture have largely proved unsuccessful. The most significant challenges facing CGT manufacturing are process analytical testing and quality control. These procedures would greatly benefit from improved sensory technologies that allow direct measurement of critical quality attributes, such as pH, oxygen, lactate and glucose. In turn, this would make manufacturing more robust, replicable and standardized. In this review, the present-day state and prospects of CGT manufacturing are discussed. In particular, the authors highlight the role of fluorescent optical sensors, focusing on their strengths and weaknesses, for CGT manufacture. The review concludes by discussing how the integration of CGT manufacture and fluorescent optical sensors could augment future bioprocessing approaches.

Simple imaging protocol for autofluorescence elimination and optical sectioning in fluorescence endomicroscopy

“…In situ monitoring of cellular health in bioreactors is a challenge for industrial bioprocessing to ensure batch-to-batch reproducibility, maximize the yield of production, and reduce the risk of contamination associated with sampling procedures [46][47][48]. In addition to the measurement of metabolites in the culture medium such as O 2 , CO 2 , or pH, production of fluorescent proteins (FPs) such as green fluorescent protein (GFP) have been recently introduced as a reporter of the status of cells or bacteria in bioreactors, which in turn allows feedback control for the culture conditions when needed [47,49] using, e.g., optogenetic tools [50,51].…”

New generation of bioreactors that advance extracellular matrix modelling and tissue engineering

“…Since the production of fluorescent nanosensors, a number of ratiometric fluorescence nanosensors for pH (Chauhan et al 2013; Orsi et al 2015; Elsutohy et al 2017) have been reported based on polymeric nanoparticles, silica nanoparticles, quantum dots, cellulose nanocrystals, latex nanobeads, and zeolite-based nanoparticles (Marín et al 2012). Overall, fluorescent nanosensors are useful for sensing due to their small size, fast response, intense signal, against relatively low background noise, relatively simple instrumental set-up, and ability to monitor non-invasively (Harrison and Chauhan 2018).…”

“…Small-scale culture of cells is typically used for in vitro research studies based on micro and milli scale volumes. Large scale culture for clinical use have been developed with volumes of up to 20,000 litres (Harrison and Chauhan 2018 ). Some examples of large scale production for clinical applications include adipose-derived stromal cells for tissue engineering (Haack-Sørensen et al 2018 ), human induced pluripotent stem cells for drug screening regenerative medicine (Yamashita et al 2018 ), megakaryocytic progenitor cell line for regenerative medicine (Retno Wahyu et al 2018 ) and mesenchymal stem cell for cartilage tissue generation (Daly et al 2018 ).…”

Augmenting Automated Analytics Using Fluorescent Nanosensors

“…Small-scale bioreactors are used for in vitro research purposes or clinical allogeneic products in commercial settings, such as chimeric antigen receptor (CAR) T cells [77]. Whereas, large-scale manufacture, which can reach batch sizes of 20,000 liters, are typically used for commercial projects [78].…”