Conventional alginate extraction from brown seaweed typically relies on harsh, non-recyclable chemicals, limiting process sustainability. This study presents temperature-responsive deep eutectic solvents (TRDES) as circular, recyclable extractants for alginate recovery. Using computational screening with COSMO-RS and experimental validation of TRDES affinity and alginate partitioning, TRDES1 (o-cresol: ethanolamine) was identified as the most promising combination, and was optimised and reused over eight cycles, yielding up to 55.6 ± 14.4 mg/g DW. COSMO-RS modelling validated the observed increase in extraction efficiency over successive cycles, showing enhanced partition coefficients and reduced Gibbs free energy of transfer with reuse. The process enabled mild extraction of functional alginate with increasing efficiency over the cycles. The main solvent parameters for TRDES design found to govern extraction and recyclability were capacity (C), partition coefficient (K), and Gibbs free energy (ΔG). Optimal performance was achieved with moderate TRDES–water capacity (1.27 × 101 to 3.15 × 101), low TRDES capacity (<1.2), and K > 1. This work establishes a theoretical framework with design rules for future TRDES development based on computational and experimental analysis and highlights the need for novel, biocompatible TRDES systems. As demonstrated, combining computational screening with these design principles enables the use of recyclable solvents. Incorporating natural compounds into TRDES design enhances both process efficiency and sustainability, facilitating the integration of DES technologies into circular biorefineries and supporting environmentally responsible biomass valorisation.

This study evaluates the impact of using deep eutectic solvents (DES), specifically betaine-urea, as a novel extraction technology for alginate from brown seaweed and its effect on the techno-functionality of the final product. Ten eutectic mixtures were assessed, with betaine-urea (BU) demonstrating the highest performance, yielding 14.9 ± 2.0 % of the total amount of alginate in the first extraction step (BU-1). Although this yield was lower than the conventional acid-alkaline (AK) method (37.6 ± 4.1 %), a sequential extraction combining water (BU-2) and alkaline conditions (BU-3) achieved higher overall yields for the BU method. The study highlights significant differences in the chemical and rheological properties of alginates extracted with BU compared to those obtained via traditional methods. BU-extracted alginates exhibited the characteristic shear-thinning behaviour of alginate solutions but with markedly higher apparent viscosity at low shear rates. BU-2 displayed gel-like behaviour (tan δ = 0.1) with a consistency index (K) 62 times higher than the acid-alkaline extract. Chemical analysis revealed a higher fraction of high-molecular-weight alginates in BU-2 and BU-3, partially explaining their increased viscosity. However, the role of betaine-urea in shaping the alginate structure and function should be further studied. This research underscores the potential of DES technology in enhancing the functionality of alginate, offering a potentially more sustainable alternative to mineral acid-base methods.

Deep eutectic solvents (DES) have emerged as green alternative extraction solvents. However, challenges in DES recovery and recycling limit their broader application. In this study, a novel thermo-separating aqueous two-phase system (ATPS) was developed for the continuous, cyclic extraction and separation of alginate from Laminaria digitata using DES and temperature-responsive copolymers. The system enables a novel approach by repeatedly reusing both the DES phase and the EOPO copolymer phase five times, thereby reducing waste generation and enhancing process sustainability. This research demonstrated that DES can be efficiently recycled for ten cycles using temperature-responsive ethylene oxide-propylene oxide (EOPO) copolymers, remaining stable yields. For the extraction and subsequent separation of alginate, three different DESs were evaluated, all of which demonstrated to extract and recover alginate. DESs ChCl:Ethylene glycol and ChCl:Urea exhibited a preference for EOPO1000 (66 and 75 % recovery, respectively), whereas Bet:Urea achieved the highest recovery with EOPO3900 (66 % recovery). Subsequent recycling of the recovered DES showed that DES could be recycled for ten cycles, maintaining stable extraction yields between 74 and 86 mg alginate/g DW and alginate recovery yields of 55–65 %. Furthermore, combined DES and EOPO recycling could be performed for up to five cycles while maintaining an alginate recovery yield between 50 and 65 mg/g DW. This thermo-separating ATPS presents a novel, circular and sustainable approach for DES recycling compared to the non-circular conventional alkaline extraction. This proposed method can be applied in a simple and effective manner to both recover and recycle DES.

The monoclonal antibody (mAb) industry is becoming increasingly digitalized. Digital twins are becoming increasingly important to test or validate processes before manufacturing. High-Throughput Process Development (HTPD) has been progressively used as a tool for process development and innovation. The combination of High-Throughput Screening with fast computational methods allows to study processes in-silico in a fast and efficient manner. This paper presents a hybrid approach for HTPD where equal importance is given to experimental, computational and decision-making stages. Equilibrium adsorption isotherms of 13 protein A and 16 Cation-Exchange resins were determined with pure mAb. The influence of other components in the clarified cell culture supernatant (harvest) has been under-investigated. This work contributes with a methodology for the study of equilibrium adsorption of mAb in harvest to different protein A resins and compares the adsorption behavior with the pure sample experiments. Column chromatography was modelled using a Lumped Kinetic Model, with an overall mass transfer coefficient parameter (k_ov). The screening results showed that the harvest solution had virtually no influence on the adsorption behavior of mAb to the different protein A resins tested. k_ov was found to have a linear correlation with the sample feed concentration, which is in line with mass transfer theory. The hybrid approach for HTPD presented highlights the roles of the computational, experimental, and decision-making stages in process development, and how it can be implemented to develop a chromatographic process. The proposed white-box digital twin helps to accelerate chromatographic process development.

The transition to continuous biomanufacturing is considered the next step to reduce costs and improve process robustness in the biopharmaceutical industry, while also improving productivity and product quality. The platform production process for monoclonal antibodies (mAbs) is eligible for continuous processing to lower manufacturing costs due to patent expiration and subsequent growing competition. One of the critical quality attributes of interest during mAb purification is aggregate formation, with several processing parameters and environmental factors known to influence antibody aggregation. Therefore, a real-time measurement to monitor aggregate formation is crucial to have immediate feedback and process control and to achieve a continuous downstream processing. Miniaturized biosensors as an in-line process analytical technology tool could play a pivotal role to facilitate the transition to continuous manufacturing. In this review, miniaturization of already well-established methods to detect protein aggregation, such as dynamic light scattering, Raman spectroscopy and circular dichroism, will be extensively evaluated for the possibility of providing a real-time measurement of mAb aggregation. The method evaluation presented in this review shows which limitations of each analytical method still need to be addressed and provides application examples of each technique for mAb aggregate characterization. Additionally, challenges related to miniaturization are also addressed, such as the design of the microfluidic chip and the microfabrication material. The evaluation provided in this review shows why the development of microfluidic biosensors is considered the key for real-time measurement of mAb aggregates and how it can contribute to the transition to a continuous processing.