Lab-scale Process Research Articles

Value creation of copra meal mannan into functional manno-oligosaccharides (β-MOS) using the mannanase Bacillus man B (BlMan26B)

Agricultural wastes rich in β-mannan are an important environmental problem in tropical and sub-tropical countries. This research aims at dealing with this and investigates the valorization of mannan-rich copra meal from virgin coconut oil manufacturing into mannan-oligosaccharides (β-MOS) by enzymatic hydrolysis using β-mannanase from Bacillus licheniformis (BlMan26B). Lab-scale process, involving pre-treatment and bioconversion steps, were conducted and evaluated. Lyophilized β-MOS was analyzed and its biological activities were assessed. The size of oligosaccharides obtained ranged from dimers to hexamers with 36.7% conversion yields. The prebiotic effects of β-MOS were demonstrated in comparison with commercial inulin and fructo-oligosaccharides (FOS). In vitro toxicity assays of β -MOS on human dermal fibroblasts and monocytes showed no cytotoxic effect. Interestingly, β-MOS at concentrations ranging from 10 to 200 µg/mL also demonstrated potent anti-inflammatory activity against LPS-induced inflammation of human macrophage THP-1 in a dose-dependent manner. However, at high dose, β-MOS could also stimulate inflammation. Therefore, further investigation must be conducted to ensure its efficacy and safe use in the future. These results indicate that β-MOS have the potential to be used as valued-added health-promoting nutraceutical or feed additive after additional in-depth studies. These finding should be applicable for other agricultural wastes rich in mannan as well.

Modelling and Validating the Nonthermal Plasma Parameters for Producing Liquid Hydrocarbon from Solid Polyolefin Wastes

This study solved a set of equations to verify the dynamic optimal conditions of nonthermal plasma (NTP)-chemical conversion of solid polyolefin wastes into liquid petroleum hydrocarbons. Furthermore, a novel optimisation model was validated with non-linear experimental conditions to assess the quantitative relationship between the process variables responsible for the degradation rate of wastes. The central composite design (CCD) experimental design was developed based on the Response Surface Model (RSM) technique. These techniques significantly improved the model predictions because of the more-detailed electrochemical description. Experiments were conducted in an in-house-designed and -developed NTP system with advanced data acquisition schemes. Both experimental and the numerical findings exhibited a good agreement, and the results indicated that the electrical factors of NTP could significantly affect the conversion yield (Yconv%) of solid polyolefin-derived wastes to liquid hydrocarbons. Additionally, the model investigation indicated that factors such as power discharge (x1), voltage intensity (x2), and reaction retention time (RTT) (x3) significantly influenced the conversion yield. After optimisation, a maximum conversion percentage (Yconv%) of ≈93% was achieved. The findings indicated that this recommended framework could be effectively employed for scaling the plasma synergistic pyrolysis technique for generating the maximal Yconv% of plastic wastes to yield an oil. Thereafter, the analysis of variance (ANOVA) technique was applied to examine the accuracy of the developed structure in order to upgrade this laboratory-scale processes to an industrial-scale process with >95% effectiveness. The calorific value of the produced oil was seen to be from 43,570.5 J/g to 46,025.5 J/g due to changes of the arrangements of the process factors, which specified that the liquid hydrocarbons showed similar characteristics like commercial diesel in this respect.

Bio-Based Materials as a Sustainable Solution for the Remediation of Contaminated Marine Sediments: An LCA Case Study.

Contaminated sediments may induce long-term risks to humans and ecosystems due to the accumulation of priority and emerging inorganic and organic pollutants having toxic and bio-accumulation properties that could become a secondary pollution source. This study focused on the screening of novel bio-based materials to be used in the decontamination of marine sediments considering technical and environmental criteria. It aimed to compare the environmental impacts of cellulose-based adsorbents produced at lab scale by using different syntheses protocols that involved cellulose functionalization by oxidation and branching, followed by structuring of an aerogel-like material via Soxhlet extraction and freeze-drying or their combination. As model pollutants, we used 4-nitrobenzaldehyde, 4-nitrophenol, methylene blue, and two heavy metals, i.e., cadmium and chromium. When comparing the three materials obtained by only employing the Soxhlet extractor with different solvents (without freeze-dying), it was observed that the material obtained with methanol did not have a good structure and was rigid and more compact than the others. A Life Cycle Assessment (LCA) was conducted to evaluate the environmental performance of the novel materials. Apart from the hierarchical categorization of the materials based on their technical and environmental performance in eliminating organic pollutants and heavy metal ions, it was demonstrated that the cellulose-based material obtained via Soxhlet extraction with ethanol was a better choice, since it had lower environmental impacts and highest adsorption capacity for the model pollutants. LCA is a useful tool to optimize the sustainability of sorbent materials alongside lab-scale experiments and confirms that the right direction to produce new performant and sustainable adsorbent materials involves not only choosing wastes as starting materials, but also optimizing the consumption of electricity used for the production processes. The main results also highlight the need for precise data in LCA studies based on lab-scale processes and the potential for small-scale optimization to reduce the environmental impacts.

Development and Characterization of Polyethylenimine-Infiltrated Mesoporous Silica Foam Pellets for CO2 Capture.

Polyethylenimine (PEI) has been shown to be promising for direct air capture (DAC) of carbon dioxide and has potential for commercial scale-up globally. Laboratory scale processes include multiple steps, such as mixing, solvent extraction, vacuum application, sonication, and various flushes and activation steps. It is critical to properly control these operating parameters to achieve higher capture capacity as a result of the optimized material configuration. This study adopts previously published pelletization processes for PEI-infiltrated mesoporous foam silica (mesoporous silica foam) to uncover the adsorption mechanisms and optimize the associated fabrication steps, such as sonication, to achieve higher sorbent productivity. A high capture capacity was achieved at 46 °C for 75 wt % PEI loading (2.27 mmol/g) followed by PEI_MSF 70 (1.81 mmol/g) and PEI_MSF 80 (1.44 mmol/g). As part of the optimization, sonication parameters of frequency, amplitude, and time were modified for PEI_MSF 75 sorbent, which resulted in the highest uptake capacity of 3.04 mmol/g (sonicated at 40 kHz and a wave amplitude of 50% for 30 s). These preliminary results would tend to prove that sonication energy affects carbon capture capacity, although there is still a lack of understanding regarding the exact underlying mechanism, suggesting the need for further investigation. It is important to note that the present work is focused on the adsorption mechanisms and not desorption or durability of the capture performance. Ongoing research addresses these factors. This paper is intended to establish baseline DAC behavior of a promising capture medium and begins probing the optimization spectrum by considering the effects of sonication energy on adsorption. Ongoing work intends to address potential abbreviations of the full range of process steps and furthers the understanding of kinetics by considering the desorption and resorption attributes.

Scalable preparation of green C-terminal amidation peptide-synthesis TAGs and the optimized TAG-assisted liquid-phase synthesis of eptifibatide

Eptifibatide is a cycloheptapeptide with C-terminal amidation and head-to-tail disulfide bridging, which has been approved as an antithrombotic drug. Currently, both at the laboratory scale and industrial level, the synthesis of eptifibatide predominantly relies on solid-phase peptide synthesis (SPPS), which is not regarded as a green sustainable and cost-effective approach to prepare eptifibatide. Herein, we have investigated the strategy employing tag-assisted liquid-phase peptide synthesis (TAG-Assisted LPPS) technology that is scalable to multi-gram scale manufacturing for eptifibatide preparation. We successfully obtained soluble Rink-Amide TAGs by esterifying organophosphorus TAG-OH with Rink-Amide, thereby facilitating the transition from synthesizing C-terminal carboxyl peptides to C-terminal amidation peptides. The products obtained during the tag-assisted coupling and Fmoc deprotection of eptifibatide intermediates can be purified through precipitation processes, eliminating the need for complex chromatographic operations. Accordingly, we developed an optimized laboratory-scale process (300 mmol) for the preparation of TAG-Rink Amide TAG, which was subsequently upscaled successfully to a 50 mmol batch synthesis of eptifibatide. The subsequent work also explores the processes of peptide cleavage and disulfide bond oxidative cyclization in eptifibatide preparation.

Towards Sustainable Material: Optimizing Geopolymer Mortar Formulations for 3D Printing: A Life Cycle Assessment Approach

Geopolymer-based concretes have been elaborated among others for their potential to lower the environmental impact of the construction sector. The rheology and workability of fresh geopolymers make them suitable for new applications such as 3D printing. In this paper, we aim to develop a potassium silicate- and metakaolin-based geopolymer mortar with sand and local earth additions suited for 3D printing and an environmental assessment framework for this material. The methodology aims at the optimization of both the granular skeleton and the geopolymer matrix for the development of a low-environmental-impact material suited for 3D printing. Using this approach, various metakaolin/earth geopolymer mortars are explored from a mechanical and environmental point of view. The environmental assessment of the lab-scale process shows an improvement for the climate change category but a degradation of other indicators, compared to Portland-cement-based concrete. Several promising options exist to further optimize the process and decrease its environmental impacts. This constitutes the main research perspective of this work.

Optimization of the Production Process of Clinical-Grade Human Salivary Gland Organoid-Derived Cell Therapy for the Treatment of Radiation-Induced Xerostomia in Head and Neck Cancer.

Head and neck cancer is a common cancer worldwide. Radiotherapy has an essential role in the treatment of head and neck cancers. After irradiation, early effects of reduced saliva flow and hampered water secretion are seen, along with cell loss and a decline in amylase production. Currently, there is no curative treatment for radiation-induced hyposalivation/xerostomia. This study aimed to develop and optimize a validated manufacturing process for salivary gland organoid cells containing stem/progenitor cells using salivary gland patient biopsies as a starting material. The manufacturing process should comply with GMP requirements to ensure clinical applicability. A laboratory-scale process was further developed into a good manufacturing practice (GMP) process. Clinical-grade batches complying with set acceptance and stability criteria were manufactured. The results showed that the manufactured salivary gland-derived cells were able to self-renew, differentiate, and show functionality. This study describes the optimization of an innovative and promising novel cell-based therapy.

Screening of salt hydrates and cellulose nanocrystal composites for thermochemical energy storage using life cycle assessment

Salt hydrate systems via thermochemical reactions can provide thermal storage for renewable-sourced alternatives to traditional heating systems like natural gas. In this study, we use life cycle analysis (LCA) along with the material prices to screen salts based on environmental impact and cost. Additionally, we performed LCA of producing a composite material of salt and cellulose nanocrystals (CNC) at a weight ratio of four to one. CNC is a stabilizing agent for salt. We assessed the salt-CNC composites based on a laboratory scale and scaled-up processing to identify low environmental impact formulations and to identify high environmental impact processes in the composite production. In general, lanthanum chloride, lithium hydroxide, and lithium chloride should be avoided due to high environmental impact or cost. For pure salts, our results showed magnesium sulfate, zinc sulfate, and calcium chloride are typically preferred with a close second tier of magnesium and strontium chlorides and strontium bromide. For the composite material, magnesium sulfate was preferred followed by zinc sulfate, sodium sulfide, and strontium chloride. CNC has a significant environmental impact, contributing over 50% of the environmental impact for these composites. Therefore, CNC production with lower environmental impacts needs to be pursued. In composite production, the environmental impact of mixing and sonication can be reduced by scaling production. However, drying remains a high-impact process. These results can help guide salt selection for other salt-based thermochemical materials and further development of the salt-CNC composite.

Integrating ex-ante and prospective life-cycle assessment for advancing the environmental impact analysis of emerging bio-based technologies

Unlike the fossil-based alternatives, many emerging bio-based technologies are still at the early lab or pilot scale and are not representative of optimized industrial conditions. This makes a robust comparison of their environmental performances via life-cycle assessment (LCA) challenging. We propose a framework to combine scaling-up projections of early-stage technologies (ex-ante LCA) with the influence of future socio-economic scenarios (prospective LCA), using a range of new bio-based polymers produced from forest residues as case study. The combined framework takes a step-by-step approach in modifying process inventories and projecting them to a future industrial scale for the environmental impact assessment. In our case study, the climate change impact from lab-scale processes decreases from 105–471 kg CO2-eq./kg of polymer to 9–14 kg CO2-eq./kg after the application of ex-ante LCA, with the highest reduction (83 %) coming from identified process synergies (e.g., solvent recovering). Combining the ex-ante and prospective LCA additionally reduces the impact up to 56 % by 2050, relative to ex-ante LCA results only. Other environmental impacts decrease as well, particularly freshwater eutrophication (up to 99 % reduction), photochemical oxidant formation (99 %), and marine eutrophication (98 %). The framework secures a more robust comparison of emerging bio-based products with conventional fossil-based alternatives, and as such it helps the identification of the improvements in both the bio-based technological processes and background supply chains that are needed to make bio-based systems outperform their fossil counterparts. A consistent integration of ex-ante and prospective LCA is instrumental to prioritize research and investments for upscaling the early-stage technologies that are most promising from a sustainability perspective, and ultimately guide a sustainable transition towards a circular bioeconomy.

233 Fermentation Characteristics of Brassica and Wheat Mixed Silages

Abstract Winter feed management in the temperate regions of the U.S. primarily consists of stored or stockpiled grasses. Recently, forage brassica species have become popular additions to fall and winter grazing programs as an alternative feed source. Most all brassicas incorporated into forage systems are grazed; however, there may be more feeding options, such as fermenting them as silage or baleage. The objective of this project was to determine, utilizing a laboratory scale process, the feasibility and quality characteristics of two different brassica species alone or mixed with winter wheat. Forages were planted in 25.4 cm pots at a seeding rate comparable with field application. Three separate forage varieties were used: a hybrid forage rapeseed (RAPE), a forage turnip (TURNIP) and winter wheat (WHEAT). Along with these 3 varieties, two mixed forage treatments were utilized; a 3-way mix spaced and covered mimicking the effect of being planted with a drill (DRILL) and a 3-way mix randomly sprinkled and left uncovered mimicking a more random application (BROADCAST). Each of these 5 treatments were replicated 5 times and grown in the greenhouse for 76 d. At the conclusion of this growing period, forages were harvested 3 cm above the soil and immediately placed into vacuum-sealed bags. Bags were placed in a dark room and incubated for a total of 83 d. Following incubation, samples were analyzed for fermentation characteristics to determine quality of the ensiling process. Data were analyzed using the MIXED procedures of SAS. There was a treatment effect (P < 0.01) on the DM of the ensiled product whereby WHEAT (31.8%) was the greatest and BROADCAST (7.1%) was the least. The BROADCAST treatment had significantly (P < 0.01) greater ammonia concentration, as well as acetic acid (P < 0.05) concentration compared with all other treatments. No differences (P = 0.26) in pH were observed within the ensiled treatments. Overall, results of this trial suggest that it might be possible to use these brassica species as an ensiled feedstuff, though further testing is necessary to elucidate possible complications or limitations.

Environmental Impact Assessment and Process Upscaling for Sustainable Production of Cellulose Nanofibre, a Biopolymer Derived from Lignocellulosic Biomass

As an agricultural waste, rice straw has a requisite quality for conversion to nanocellulose; however, the environmental and technical feasibility of the processes available has not been assessed at commercial scale. Therefore, in the present work commercialization and environmental impacts of the cellulose nanofibre (CNF) production from rice straw were evaluated by scaling up the laboratory-scale process to the pilot scale level. Life cycle assessment (LCA) of the laboratory scale process showed the maximum impact of electricity (161 kg CO2 eq) and sodium hydroxide (7.82 kg CO2 eq) on global warming potential; though, the overall impacts got reduced approximately three times (~51 kg CO2 eq for electricity) with the scale-up of the process. When compared with the reported literature both the scales of production were found to have lesser environmental impacts. Further, the techno-economic feasibility of the process was evaluated at different plant capacities for the optimum minimum selling price (MSP) of CNF. At the plant capacity of 15 kg/day, the MSP of CNF was calculated as $16,537.36/tonne dropped to $14,944.87 and $14,590.98/tonne with the increased batch capacity of 30 kg/day and 45 kg/day, respectively. Through sensitivity analysis, the MSP of CNF was observed to be highly sensitive to the cost of capital investment and chemicals cost. In addition, analysis of the uncertainty associated with the identified cost drivers reflects the scope for inherited risks, as determined by the Monte-Carlo simulation method. This study established an environmentally and economically sustainable process for commercialisation of nanocellulose production from agricultural waste at a minimum cost of production.

Comparison of two lab-scale protocols for enhanced mRNA-based CAR-T cell generation and functionality

Process development for transferring lab-scale research workflows to automated manufacturing procedures is critical for chimeric antigen receptor (CAR)-T cell therapies. Therefore, the key factor for cell viability, expansion, modification, and functionality is the optimal combination of medium and T cell activator as well as their regulatory compliance for later manufacturing under Good Manufacturing Practice (GMP). In this study, we compared two protocols for CAR-mRNA-modified T cell generation using our current lab-scale process, analyzed all mentioned parameters, and evaluated the protocols’ potential for upscaling and process development of mRNA-based CAR-T cell therapies.

Digesters as heat storage: Effects of the digester temperature on the process stability, sludge liquor quality, and the dewaterability.

Variation of the digester temperature during the year enables the operation of digesters as seasonal heat storage contributing to a holistic heat management at water resource recovery facilities. Full- and lab-scale process data were conducted to examine the effect of the digester temperature on process stability, sludge liquor quality, and dewaterability. Both full- and lab-scale digesters show a stable anaerobic degradation process with a hydraulic retention time of more than 20 days and organic load rates up to 2.2-kg COD/(m3 ·day) at temperatures between 33 and 53°C. The concentrations of soluble COD and ammonium-nitrogen in the sludge liquor digested at 53°C are 2.6 to 5.8 times and 1.3 times higher, respectively, than in the sludge liquor digested at 37°C. Dewatering tests show an enhancement of the dewaterability but a clear increase in the polymer demand at increased digester temperature. PRACTITIONER POINTS: Digesters can operate as seasonal heat storage within mesophilic and thermophilic temperatures Stable anaerobic degradation process for HRT above 20 days Maintenance of process stability as well as quantity and quality of biogas Increase of soluble COD in sludge liquor at higher temperatures Better dewaterability but higher demand for polymers with increasing temperature.

Lab-scale Process Parameter Determination of a Two-stage DRI (direct reduced iron) Process Using Reformed COG (coke oven gas)

On the road to carbon neutrality, a great deal of attention is being paid to emerging technologies such as the DRI (direct reduced iron) process. This study proposes a two-stage DRI process using reformed COG (coke oven gas), and determined optimal process parameters. The reduction and carbonization of Carajás iron ore used in the field were examined by monitoring the weight loss of the samples, and EDS and XRD measurements with respect to the reaction temperature and operating time for different reducing environments. While the reduction of iron ore is completed in 60 min at 800oC regardless of the reducing environment, the carbonization of reduced iron is attainable only at 800oC with high hydrogen content in the reducing gas. Thus, a countercurrent scheme in the proposed DRI process is justified, in which COG containing high hydrogen content is flowed into the 2nd stage operated at 800oC and subsequently directed to the 1st stage operated at 600oC. The reduction of iron ore is initiated in the 1st stage for 60 min irrespective of the reducing environment, and the completion of the reduction and the following carbonization is fulfilled in the 2nd stage for 40 min under a high reducing environment. An equilibrium analysis supported that the cracking of CH4 in COG to graphite leads to the formation of CO from CO2 and the successive formation of Fe3C from reduced Fe. The carbonization of iron ore is possible only in the presence of CO2 . It also showed that too high or low reducing environments are not desirable to accomplish the DRI process. This study is expected to be provide an effective guideline for optimizing similar DRI processes.

Life cycle assessment of face mask decontamination via atmospheric pressure plasma

Since the start of the COVID-19 pandemic, the use of face masks to prevent transmission of infection has increased. One way to reduce impacts of the production of new masks (including reduction of resource use) is to implement circular economy strategies to allow multiple (re)uses of the face masks. In the present study, the environmental impacts of single use disposable masks in hospital are compared with their potential decontamination and reuse using the low temperature plasma (LTP) decontamination process. For all the considered scenarios, it resulted that environmental impacts of single use of disposable masks are lower (for every impact category) compared with decontamination and reuse of face masks. Highest impact in the decontamination process is due to helium used for cooling the electrodes, causing more than 95% of the impacts in most of the impact categories. To decrease impacts of decontamination, two improvement scenarios were assessed: 1) helium replacement with alternative materials (as argon or nitrogen), and 2) decreased helium consumption (based on optimized helium flow, or helium recirculation). Replacing helium with alternative materials does not lead to environmental benefits, while optimising the helium consumption could make the decontaminating more environmental friendly, but only if helium consumption in the current laboratory practise would be decreased by at least 95%. This assessment takes into consideration that the decontamination is still based on laboratory scale process, and for which additional research to optimize the process from a resource and environmental point of view is needed.

Valorisation of waste olive pomace: Laboratory and pilot scale processing to extract dietary fibre

The olive oil industry generates large quantities of waste pomace which has the potential to be used in a range of applications, including as a source of dietary fibre in the food ingredients sector. This study determined that hexane extracted olive pomace still retained 10.6% soluble dietary fibre (SDF) although the total sugar content of 27% was low. The lower and upper yields from single trials on freeze dried olive pomace (10 g) for hexane extracted IDF (insoluble dietary fibre) and SDF were 41–53% and 0.5–2.5%, respectively. These results tentatively indicated that pH and homogenization (high shear mixing) were important factors that affect IDF and SDF yields. The pilot scale processing of 36 kg (wet weight) frozen olive pomace, equivalent to 5.65 kg (dry weight), focused on recovery yield of SDF using an alkaline treatment approach combined with wet milling (2 h). There was no increase in microbial contamination during the trial. While a relatively high yield of SDF (5.6%) was obtained, the monosaccharide content was low, and this fraction did not exhibit gelation properties which is one of the key indicators for functionality in the food ingredients sector. A lower-than-expected IDF yield (13.6%) was obtained during the pilot trial compared with initial laboratory results (41.3–53.0%). However, this process enriched the fibre content from 40% to more than 70% in the majority of the IDF samples collected during the pilot trial. It was determined that the highest water and oil holding capacities in these samples were 6.9 and 4.1, respectively, which were associated with IDF extracted at pH 4.5. This study revealed that SDF could be recovered from olive pomace and the recovery of IDF could be scaled up, where physical disruption and pH conditions caused apparent changes in the yields, and the water and oil holding capacities of dietary fibre fractions.

Analyzing the environmental impact of recovering critical materials from spent lithium-ion batteries through statistical optimization

The exponential growth of the lithium-ion battery industry has heightened interest in recycling critical metals such as lithium, manganese, cobalt, and nickel. This research focused on optimizing the leaching process parameters using inorganic acids (HCl, HNO3, and H2SO4) to recover these elements from cathode powders via hydrometallurgy. A statistical tool was utilized to optimize several parameters, including temperature, leaching time, the concentration of acids, solid-to-liquid ratio, and % volume of H2O2, to achieve the highest recovery percentage for critical metals. To evaluate the environmental impact of optimized processes at the laboratory scale, this study proposed a novel scheme that integrates the Design of Experiments and Life Cycle Assessment methodologies. Sulfuric acid was identified as the best inorganic acid for recovering critical materials from NMC 532 cathode powder, with all optimized conditions for each acid showing better environmental performance than those found in the literature. This research provides significant preliminary insights into the sustainability assessment of metal recovery from spent lithium-ion batteries. The proposed environmental impact methodology can be expanded to larger system boundaries of laboratory-scale processes, providing a comprehensive framework for assessing the environmental impact of metal recovery from spent lithium-ion batteries.

Reduction of ethanol content in wine with an improved combination of yeast strains and process conditions

One interesting strategy to address the increasing alcohol content of wines, associated with climate change, is to reduce the ethanol yield during fermentation. Within this strategy, the approach that would allow the clearest reduction in alcohol content is the respiration of part of the grape sugars by yeasts. Non-Saccharomyces species can be used for this purpose but suffer from a limited ability to dominate the process and complete fermentation. In turn, Saccharomyces cerevisiae shows a high production of acetic acid under the growth conditions required for respiration. Previously proposed procedures used combinations of non-Saccharomyces and S. cerevisiae starters, or a strain of S. cerevisiae (PR1018), with unique metabolic properties. In both cases, precise management of oxygen availability was required to overcome the acetic acid problem. In this work, we have developed a laboratory scale process to take advantage of the properties of PR1018 and a strain of Metschnikowia pulcherrima. This process is more robust than the previous ones and does not rely on strict control of oxygenation or even the use of this particular strain of S. cerevisiae. Aeration can be interrupted instantly without impairing the volatile acidity. Under the selected conditions, an ethanol reduction of around 3% (v/v) was obtained compared to the standard fermentation control.

Effect of heat transfer on the pressurization, extraction, and depressurization stages of a supercritical CO2 extraction process. 1. Development and validation of the heat transfer model

We modeled and simulated the heat and mass transfer in the depressurization, pressurization, and extraction stages of a supercritical CO2 extraction process. Parameters of a Nusselt correlation for convective wall-to-fluid heat transfer coefficient were best fitted to experimental temperatures during the depressurization of vessels packed with different materials. Heat transfer in the pressurization and extraction stages was simulated predictively using this correlation and compared with literature laboratory-scale, pressurization, and extraction data. In depressurization, simulated temperature, pressure, and vented mass flow profiles agreed reasonably well with experimental values, as the calculated Mean Absolute Percent Error (MAPE) was 1.8% for the temperature. For pressurization, simulated values of final temperatures and pressures fell within a standard deviation of experimental data, estimating a MAPE of 3.9% for temperature and 5.2% for pressure. In the extraction stage, including radial and axial temperature gradients in the mass transfer model reduced the error (about 2%) of simulated cumulative extraction curves against experimental values compared to those obtained when neglecting radial variations in temperature. These results are significant because they prove that heat transfer phenomena may impact industrial more considerably than laboratory-scale processes.

A Soft Skin Adhesive (SSA) Patch for Extended Release of Pirfenidone in Burn Wounds.

As much as half or more of deep partial-thickness burn wounds develop hypertrophic scarring and contracture. Once formed, treatments are only minimally effective. Pirfenidone (Pf), indicated for treatment of idiopathic pulmonary fibrosis, is an anti-inflammatory and anti-fibrotic small molecule that potentially can be repurposed as a preventative against scarring in burn wounds. We present a drug-in-matrix patch with a soft skin adhesive (SSA) wound-contacting layer for multi-day drug delivery of Pf into burn wounds at the point of injury. Our patch construction consists of an SSA adhesive layer (Liveo™ MG7-9850, Dupont, Wilmington, DE, USA) for wound fixation, an acrylic co-polymer drug matrix (DURO-TAK 87-2852, Henkel, Düsseldorf, Germany) as the drug (Pf) reservoir, and an outermost protective polyurethane backing. By employing a drug-in-matrix patch design, Pf can be loaded as high as 2 mg/cm2. Compared to the acrylic co-polymer adhesive patch preparations and commercial films, adding an SSA layer markedly reduces skin stripping observed under scanning electron microscopy (SEM). Moreover, the addition of varying SSA thicknesses did not interfere with the in vitro release kinetics or drug permeation in ex vivo porcine skin. The Pf patch can be easily applied onto and removed from deep partial-thickness burn wounds on Duroc pigs. Continuous multi-day dosing of Pf by the patches (>200 μg/cm2/day) reduced proinflammatory biomarkers in porcine burn wounds. Pf patches produced by the manual laboratory-scale process showed excellent stability, maintaining intact physical patch properties and in vitro biological activity for up to one year under long-term (25 °C at 60% RH) and 6 months under accelerated (40 °C at 75% RH) test conditions. To manufacture our wound safe-and-extended-release patch, we present scale-up processes using a machine-driven automated roll-to-roll pilot scale coater.