Innovations in cell culture-based influenza vaccine manufacturing - from static cultures to high cell density cultivations

Influenza remains a serious global health concern, causing significant morbidity and mortality each year. Vaccination is crucial to mitigate its impact, but requires rapid and efficient manufacturing strategies to handle timing and supply. Traditionally relying on egg-based production, the field has witnessed a paradigm shift toward cell culture-based methods offering enhanced flexibility, scalability, and process safety. This review provides a concise overview of available cell substrates and technological advancements. We summarize crucial steps toward process intensification - from roller bottle production to dynamic cultures on carriers and from suspension cultures in batch mode to high cell density perfusion using various cell retention devices. Moreover, we compare single-use and conventional systems and address challenges including defective interfering particles. Taken together, we describe the current state-of-the-art in cell culture-based influenza virus production to sustainably meet vaccine demands, guarantee a timely supply, and keep up with the challenges of seasonal epidemics and global pandemics.

Self-assembled protein vesicles as vaccine delivery platform to enhance antigen-specific immune responses

Self-assembling protein nanoparticles are beneficial platforms for enhancing the often weak and short-lived immune responses elicited by subunit vaccines. Their benefits include multivalency, similar sizes as pathogens and control of antigen orientation. Previously, the design, preparation, and characterization of self-assembling protein vesicles presenting fluorescent proteins and enzymes on the outer vesicle surface have been reported. Here, a full-size model antigen protein, ovalbumin (OVA), was genetically fused to the recombinant vesicle building blocks and incorporated into protein vesicles via self-assembly. Characterization of OVA protein vesicles showed room temperature stability and tunable size. Immunization of mice with OVA protein vesicles induced strong antigen-specific humoral and cellular immune responses. This work demonstrates the potential of protein vesicles as a modular platform for delivering full-size antigen proteins that can be extended to pathogen antigens to induce antigen specific immune responses.

The current status of various preclinical therapeutic approaches for tendon repair

Tendons are fibroblastic structures that link muscle and bone. There are two kinds of tendon injuries, including acute and chronic. Each form of injury or deterioration can result in significant pain and loss of tendon function. The recovery of tendon damage is a complex and time-consuming recovery process. Depending on the anatomical location of the tendon tissue, the clinical outcomes are not the same. The healing of the wound process is divided into three stages that overlap: inflammation, proliferation, and tissue remodeling. Furthermore, the curing tendon has a high re-tear rate. Faced with the challenges, tendon injury management is still a clinical issue that must be resolved as soon as possible. Several newer directions and breakthroughs in tendon recovery have emerged in recent years. This article describes tendon injury and summarizes recent advances in tendon recovery, along with stem cell therapy, gene therapy, Platelet-rich plasma remedy, growth factors, drug treatment, and tissue engineering. Despite the recent fast-growing research in tendon recovery treatment, still, none of them translated to the clinical setting. This review provides a detailed overview of tendon injuries and potential preclinical approaches for treating tendon injuries.

Design of deep eutectic solvents for multiple perfluoroalkyl substances removal: Energy-based screening and mechanism elucidation

The current landscape of perfluoroalkyl substances (PFAS) extraction methodologies presents significant challenges, particularly for multiple PFAS with different carbon chain lengths. This study introduced an energy-driven strategic approach for screening deep eutectic solvents (DESs) to effectively remove a diverse range of PFAS, including perfluoroalkylcarboxylic acids (PFCAs), perfluoroalkanesulfonic acids (PFSAs), and perfluoroalkyl amides (FAAs), from contaminated environments (total 13 target compounds). Utilizing energy-based screening, we identified DES candidates with high affinity for a spectrum of PFAS compounds from 1234 potential starting materials of eutectic systems. Key findings revealed the superior removal efficiency of tributylphosphineoxide/2-methylpiperazine system, exceeding 99 % for various PFAS with different carbon chain lengths in real environmental water samples. Additionally, we elucidated the molecular interactions between DESs and PFAS through ab initio molecular dynamics (AIMD) simulations, providing valuable insights into the mechanisms governing the removal process. The mechanism of extraction involves hydrogen bond network topology and structural organization, with DESs capable of extracting PFAS while maintaining a weakly aggregated state of target molecules and minimizing the impact on the intrinsic structures of DES. The proposed system forms a dynamic, complementary, and flexible non-covalent interaction network structure with PFAS. The study advances the understanding of DES as a designable, effective, and sustainable alternative to conventional solvents for PFAS remediation, offering a significant contribution to environmental chemistry and green technology.

Drying kinetics and energy efficiency of soot ash of smelting silicon manganese alloys under microwave heating

When smelting silicon manganese alloy in an industrial electric furnace, it will produce smoke and dust waste gas, which can be utilized again back to the furnace and improve the utilization rate of raw materials after a particular trapping device and collection treatment. However, at higher moisture levels, they are prone to explode. Effects of various initial masses, initial moisture contents, and microwave output powers on the soot ash of smelting silicon manganese alloy were studies. The findings indicate that the microwave drying rate increases with all three variables. The time for complete microwave drying is directly proportional to the sample's initial moisture content and the sample's initial mass, and the time for complete microwave drying is inversely proportional to the microwave output power. The results demonstrate that the Modified Page model can accurately describe the microwave drying process. The experimental data were fitted experimentally by drying kinetic models. Microscopic characterization of soot ash from refining silico‑manganese alloys before and after drying was carried out using FTIR and SEM. Through FTIR characterization, the peak value of the -OH absorption peak decreases upon drying, and SEM results in no agglomeration caused by microwave drying and better dispersion of the soot ash of the dried smelted silica‑manganese alloys, all of which proved that microwaves could effectively remove water. It was discovered that the diffusion coefficient increased gradually with increasing power when it was computed using Fick's second law. The diffusion coefficient increases and then decreases as the moisture content increases. The diffusion coefficient decreases as the initial mass increases. Activation energy of microwave drying of soot ash from the refining of silicomanganese alloys was calculated to be -1.4467 W/g. Its purpose is to offer a detailed guide for the industrial drying of soot ash from silicomanganese alloy refinement using microwave drying technology.

Recent advances in soft, implantable electronics for dynamic organs

Unlike conventional rigid counterparts, soft and stretchable electronics forms crack- or defect-free conformal interfaces with biological tissues, enabling precise and reliable interventions in diagnosis and treatment of human diseases. Intrinsically soft and elastic materials, and device designs of innovative configurations and structures leads to the emergence of such features, particularly, the mechanical compliance provides seamless integration into continuous movements and deformations of dynamic organs such as the bladder and heart, without disrupting natural physiological functions. This review introduces the development of soft, implantable electronics tailored for dynamic organs, covering various materials, mechanical design strategies, and representative applications for the bladder and heart, and concludes with insights into future directions toward clinically relevant tools.

Facile preparation and characterization of biodegradable and biocompatible UV shielding transdermal patches based on natural rubber latex- dextrin blends

The physico-chemical and biological properties of natural rubber latex (NRL), entailing its biodegradability and biocompatibility, render it a promising material for various biomedical applications. This research explores the facile blending of NRL with dextrin in different compositions to investigate its potential as a prospective UV shielding transdermal patch for biomedical applications. The superior compatibility between the polymers after blending and the improved thermal stability have been established through FTIR, DSC, and TGA examinations, respectively. Optimization of blended polymers for compatibility, wettability, crystallinity, and static mechanical properties has been performed. Morphology characterization conducted via SEM and AFM techniques suggests a uniform morphology for the optimized blend system. The UV shielding ability of the blend has been confirmed by the evaluation of in-vitro UV shielding performance, UV protection factor (UPF), and the superior protection of the optimized system on living cells upon UV irradiation. The observed cell viability, swelling, erosion, porosity, hemocompatibility, and soil degradation properties suggest the NRL-DXT combination for the possible development of high-quality transdermal patches.

Increasing the stability of electrolyte-gated organic synaptic transistors for neuromorphic implants

Electrolyte-gated organic synaptic transistors (EGOSTs) can have versatile synaptic plasticity in a single device, so they are promising as components of neuromorphic implants that are intended for use in neuroprosthetic electronic nerves that are energy-efficient and have simple system structure. With the advancement in transistor properties of EGOSTs, the commercialization of neuromorphic implants for practical long-term use requires consistent operation, so they must be stable in vivo. This requirement demands strategies that maintain electronic and ionic transport in the devices while implanted in the human body, and that are mechanically, environmentally, and operationally stable. Here, we cover the structure, working mechanisms, and electrical responses of EGOSTs. We then focus on strategies to ensure their stability to maintain these characteristics and prevent adverse effects on biological tissues. We also highlight state-of-the-art neuromorphic implants that incorporate these strategies. We conclude by presenting a perspective on improvements that are needed in EGOSTs to develop practical, neuromorphic implants that are long-term useable.

Green and efficient extraction of flavonoids from Perilla frutescens (L.) Britt. leaves based on natural deep eutectic solvents: Process optimization, component identification, and biological activity

In this study, an ultrasonic-assisted natural deep eutectic solvent (NaDES) was used to extract flavonoids from Perilla frutescens (L.) Britt. leaves. Of 10 tested NaDESs, that comprising D-(+)-glucose and glycerol exhibited the best total flavonoid extraction rate. Response surface methodology (RSM) was used for extraction modeling and optimization, and the total flavonoid content reached 87.48 ± 1.61 mg RE/g DW, which was a significant increase of 5.36% compared with that of 80% ethanol extraction. Morphological changes in P. frutescens leaves before and after extraction were analyzed by scanning electron microscopy (SEM), and the mechanism of NaDES formation was studied by Fourier transform infrared (FT-IR) spectroscopy. Furthermore, 10 flavonoids were identified by UPLC-Q-TOF-MS. In addition, the NaDES extract had better biological activity according to five kinds of antioxidant capacity measurements, cyclooxygenase-2 (COX-2) and hyaluronidase (Hyal) inhibition experiments. Moreover, the stability test revealed that the total flavonoid loss rate of the NaDES extract after four weeks was 37.75% lower than that of the ethanol extract. These results indicate that the NaDES can effectively extract flavonoids from P. frutescens leaves and provide a reference for further applications in the food, medicine, health product and cosmetic industries.

A continuous micro-feeder for cohesive pharmaceutical materials

Over the past decade, continuous manufacturing has garnered significant attention in the pharmaceutical industry. Still, numerous continuous unit operations need developments, such as powder blending and feeding at low and high throughputs. Especially the continuous and consistent feeding of solid drug substances and excipients at low feed rates remains challenging. This study demonstrates a micro-feeder capable of feeding poorly-flowing pharmaceutical powders at low feed rates. The system performance was investigated using three grades of pharmaceutical powder: croscarmellose sodium (cohesive), magnesium stearate (very cohesive), and an active ingredient, paracetamol (non-flowing). The results show that the micro-feeder can continuously and consistently feed powders at low flow rates (<20 g/h) with low variability (<10 % for non-flowing materials and < 5 % for cohesive materials). Notably, the micro-feeder achieves these results without any feedback control and remains unaffected by refilling, making it a truly versatile and industry-relevant solution. The study's results demonstrate that this micro-feeder system effectively tackles the challenge of consistent and accurate powder feeding at low rates.

Recent progress of microneedles in transdermal immunotherapy: A review

Since human skin is an immune organ, a large number of immune cells are distributed in the epidermis and the dermis of the skin. Transdermal immunotherapy shows great therapeutic advantages in innate immunotherapy and adaptive immunotherapy. To solve the problem that macromolecules are difficult to penetrate into the skin, the microneedle technology can directly break through the skin barrier using micron-sized needles in a non-invasive and painless way for transdermal drug delivery. Therefore, it is considered to be an effective technology to increase drug transdermal absorption. In this review, the types of preparation, the combinations with different techniques and the mechanisms of microneedles in transdermal immunotherapy were summarized. Compared with traditional immunotherapy like intramuscular injection and subcutaneous injection, the microneedle has many advantages in transdermal immunotherapy, such as reducing patient pain, enhancing vaccine stability, and inducing stronger immune responses. Although there are still some limitations to be solved, the application of microneedle technology in transdermal immunotherapy is undoubtedly a promising means of drug delivery.

Hydrophobic binary mixtures containing amphotericin B as lipophilic solutions for the treatment of cutaneous leishmaniasis

Cutaneous leishmaniasis, caused by Leishmania parasites, requires treatments with fewer side effects than those currently available. The development of a topical solution based on amphotericin B (AmB) was pursued. The considerable interest in deep eutectic solvents (DESs) and their remarkable advantages inspired the search for a suitable hydrophobic excipient. Various mixtures based on commonly used hydrogen bond donors (HBDs) and acceptors (HBAs) for DES preparations were explored. Initial physical and in-vitro screenings showed the potential of quaternary phosphonium salt-based mixtures. Through thermal analysis, it was determined that most of these mixtures did not exhibit eutectic behavior. X-ray scattering studies revealed a sponge-like nanoscale structure. The most promising formulation, based on a combination of trihexyl(tetradecyl)phosphonium chloride and 1-oleoyl-rac-glycerol, showed no deleterious effects through histological evaluation. AmB was fully solubilized at concentrations between 0.5 and 0.8 mg·mL-1, depending on the formulation. The monomeric state of AmB was observed by circular dichroism. In-vitro irritation tests demonstrated acceptable viability for AmB-based formulations up to 0.5 mg·mL-1. Additionally, an ex-vivo penetration study on pig ear skin revealed no transcutaneous passage, confirming AmB retention in healthy, unaffected skin.

Therapeutic delivery of CCL2 modulates immune response and restores host-microbe homeostasis

Many chronic inflammatory diseases are attributed to disturbances in host-microbe interactions, which drive immune-mediated tissue damage. Depending on the anatomic setting, a chronic inflammatory disease can exert unique local and systemic influences, which provide an exceptional opportunity for understanding disease mechanism and testing therapeutic interventions. The oral cavity is an easily accessible environment that allows for protective interventions aiming at modulating the immune response to control disease processes driven by a breakdown of host-microbe homeostasis. Periodontal disease (PD) is a prevalent condition in which quantitative and qualitative changes of the oral microbiota (dysbiosis) trigger nonresolving chronic inflammation, progressive bone loss, and ultimately tooth loss. Here, we demonstrate the therapeutic benefit of local sustained delivery of the myeloid-recruiting chemokine (C-C motif) ligand 2 (CCL2) in murine ligature-induced PD using clinically relevant models as a preventive, interventional, or reparative therapy. Local delivery of CCL2 into the periodontium inhibited bone loss and accelerated bone gain that could be ascribed to reduced osteoclasts numbers. CCL2 treatment up-regulated M2-macrophage and downregulated proinflammatory and pro-osteoclastic markers. Furthermore, single-cell ribonucleic acid (RNA) sequencing indicated that CCL2 therapy reversed disease-associated transcriptomic profiles of murine gingival macrophages via inhibiting the triggering receptor expressed on myeloid cells-1 (TREM-1) signaling in classically activated macrophages and inducing protein kinase A (PKA) signaling in infiltrating macrophages. Finally, 16S ribosomal ribonucleic acid (rRNA) sequencing showed mitigation of microbial dysbiosis in the periodontium that correlated with a reduction in microbial load in CCL2-treated mice. This study reveals a novel protective effect of CCL2 local delivery in PD as a model for chronic inflammatory diseases caused by a disturbance in host-microbe homeostasis.

Combined experimental and computational investigation of tetrabutylammonium bromide-carboxylic acid-based deep eutectic solvents

Aiming at shedding light on the molecular interactions in deep eutectic solvents (DESs), the DESs based on tetrabutylammonium bromide (TBAB) as hydrogen bond acceptor (HBA) and carboxylic acids (CAs) (formic acid (FA), oxalic acid (OA), and malonic acid (MA)) as hydrogen bond donor (HBD) were investigated by both experimental and theoretical techniques. The thermal behaviors of the prepared DESs were investigated by differential scanning calorimetry (DSC) method. In order to study the hydrogen bond formation between the DESs constituents, the FT-IR analysis was carried out. The large positive deviations of the iso solvent activity lines of ternary HBA + HBD + 2-propanol mixtures determined by the isopiestic technique from the semi-ideal behavior indicate that CAs interact strongly with TBAB and therefore they can form DESs. Molecular dynamics (MD) simulations were performed to present an atomic-scale image of the components and describe the microstructure of DESs. From the MD simulations, the radial distribution functions (RDFs), coordination numbers (CNs), combined distribution functions (CDFs), and spatial distribution functions (SDFs) were calculated to investigate the interaction between the components and three-dimensional visualization of the DESs. The obtained results confirmed the importance of hydrogen bonds in the formation of TBAB/CAs DESs.

Multi-cell-line learning for the data-driven construction of mechanistic metabolic models

Mammalian cells are commonly used as hosts in cell culture for biologics production in the pharmaceutical industry. Structured mechanistic models of metabolism have been used to capture complex cellular mechanisms that contribute to varying metabolic shifts in different cell lines. However, little research has focused on the impact of temporal changes in enzyme abundance and activity on the modeling of cell metabolism. In this work, we present a framework for constructing mechanistic models of metabolism that integrate growth-signaling control of enzyme activity and transcript dynamics. The proposed approach is applied to build models for three Chinese hamster ovary (CHO) cell lines using fed-batch culture data and time-series transcript profiles. Leveraging information from the transcriptome data, we develop a parameter estimation approach based on multi-cell-line (MCL) learning, which combines data sets from different cell lines and trains the individual cell-line models jointly to improve model accuracy. The computational results demonstrate the important role of growth signaling and transcript variability in metabolic models as well as the virtue of the MCL approach for constructing cell-line models with a limited amount of data. The resulting models exhibit a high level of accuracy in predicting distinct metabolic behaviors in the different cell lines; these models can potentially be used to accelerate the process and cell-line development for the biomanufacturing of new protein therapeutics.

Recent advances in artificial intelligent strategies for tissue engineering and regenerative medicine

BACKGROUND

Tissue engineering and regenerative medicine (TERM) aim to repair or replace damaged or lost tissues or organs due to accidents, diseases, or aging, by applying different sciences. For this purpose, an essential part of TERM is the designing, manufacturing, and evaluating of scaffolds, cells, tissues, and organs. Artificial intelligence (AI) or the intelligence of machines or software can be effective in all areas where computers play a role.

METHODS

The "artificial intelligence," "machine learning," "tissue engineering," "clinical evaluation," and "scaffold" keywords used for searching in various databases and articles published from 2000 to 2024 were evaluated.

RESULTS

The combination of tissue engineering and AI has created a new generation of technological advancement in the biomedical industry. Experience in TERM has been refined using advanced design and manufacturing techniques. Advances in AI, particularly deep learning, offer an opportunity to improve scientific understanding and clinical outcomes in TERM.

CONCLUSION

The findings of this research show the high potential of AI, machine learning, and robots in the selection, design, and fabrication of scaffolds, cells, tissues, or organs, and their analysis, characterization, and evaluation after their implantation. AI can be a tool to accelerate the introduction of tissue engineering products to the bedside.

HIGHLIGHTS

The capabilities of artificial intelligence (AI) can be used in different ways in all the different stages of TERM and not only solve the existing limitations, but also accelerate the processes, increase efficiency and precision, reduce costs, and complications after transplantation. ML predicts which technologies have the most efficient and easiest path to enter the market and clinic. The use of AI along with these imaging techniques can lead to the improvement of diagnostic information, the reduction of operator errors when reading images, and the improvement of image analysis (such as classification, localization, regression, and segmentation).

Novel quinazoline sulfonamide-based scaffolds modulate methicillin-resistant Staphylococcus aureus (MRSA) pneumonia in immunodeficient irradiated model: Regulatory role of TGF-β

A library of new quinazoline pharmacophores bearing benzenesulfonamide moiety was designed and synthesized. Compounds 3a-n were screened for their in vitro antimicrobial activity against eight multidrug-resistant clinical isolates. Compounds 3d and 3n exhibited prominent antibacterial activity, specifically against MRSA. After exhibiting relative in vitro and in vivo safety, compound 3n was selected to assess its anti-inflammatory activity displaying promising COX-2 inhibitory activity compared to Ibuprofen. In vivo experimental MRSA pneumonia model was conducted on immunodeficient (irradiated) mice to reveal the antimicrobial and anti-inflammatory responses of compound 3n compared to azithromycin (AZ). Treatment with compound 3n (10 and 20 mg/kg) as well as AZ resulted in a significant decrease in bacterial counts in lung tissues, suppression of serum C-reactive protein (CRP), lung interleukin-6 (IL-6), myeloperoxidase activity (MPO) and transforming growth factor-β (TGF-β). Compound 3n showed a non-significant deviation of lung TGF-β1 from normal values which in turn controlled the lung inflammatory status and impacted the histopathological results. Molecular docking of 3n showed promising interactions inside the active sites of TGF-β and COX-2. Our findings present a new dual-target quinazoline benzenesulfonamide derivative 3n, which possesses significant potential for treating MRSA-induced pneumonia in an immunocompromised state.

Recent advancement of sonogenetics: A promising noninvasive cellular manipulation by ultrasound

Recent advancements in biomedical research have underscored the importance of noninvasive cellular manipulation techniques. Sonogenetics, a method that uses genetic engineering to produce ultrasound-sensitive proteins in target cells, is gaining prominence along with optogenetics, electrogenetics, and magnetogenetics. Upon stimulation with ultrasound, these proteins trigger a cascade of cellular activities and functions. Unlike traditional ultrasound modalities, sonogenetics offers enhanced spatial selectivity, improving precision and safety in disease treatment. This technology broadens the scope of non-surgical interventions across a wide range of clinical research and therapeutic applications, including neuromodulation, oncologic treatments, stem cell therapy, and beyond. Although current literature predominantly emphasizes ultrasonic neuromodulation, this review offers a comprehensive exploration of sonogenetics. We discuss ultrasound properties, the specific ultrasound-sensitive proteins employed in sonogenetics, and the technique's potential in managing conditions such as neurological disorders, cancer, and ophthalmic diseases, and in stem cell therapies. Our objective is to stimulate fresh perspectives for further research in this promising field.

Regulatory trends in engineering bioactive-phytocompounds

The secondary plant metabolites are of enormous importance because of their extensive medicinal, nutraceutical, and industrial applications. In plants, these secondary metabolites are often found in extremely small amounts, therefore, following the discovery of any prospective metabolite, the main constraining element is the ability to generate enough material for use in both industrial and therapeutic settings. In order to satisfy the rising demand for value-added metabolites, researchers prefer to use different molecular approaches for scalable and sustainable production of these phytocompounds. Here, we discuss the emerging regulatory trends in engineering these bioactive-phytocompounds and provide recommendation on successful employment of these state-of-the-art technologies for translation of these academic researches into novel process and products.

Research progress in the development of 3D skin models and their application to in vitro skin irritation testing

Toxicological assessment of chemicals is crucial for safeguarding human health and the environment. However, traditional animal experiments are associated with ethical, technical, and predictive limitations in assessing the toxicity of chemicals to the skin. With the recent development of bioengineering and tissue engineering, three-dimensional (3D) skin models have been commonly used as an alternative for toxicological studies. The skin consists of the subcutaneous, dermis, and epidermis. All these layers have crucial functions such as physical and biological protection and thermoregulation. The epidermis is the shallowest layer protecting against external substances and media. Because the skin is the first contact point for many substances, this organ is very significant for assessing local toxicity following skin exposure. According to the classification of the United Nations Global Harmonized System, skin irritation is a major potentially hazardous characteristic of chemicals, and this characteristic must be accurately assessed and classified for enhancing chemical safety management and preventing and reducing chemical accidents. This review discusses the research progress of 3D skin models and introduces their application in assessing chemical skin irritation.

Mind the Gap: The Role of Mass Transfer in Shaped Nanoporous Adsorbents for Carbon Dioxide Capture

Adsorptive separations by nanoporous materials are major industrial processes. The industrial importance of solid adsorbents is only expected to grow due to the increased focus on carbon dioxide capture technology and energy-efficient separations. To evaluate the performance of an adsorbent and design a separation process, the adsorption thermodynamics and kinetics must be known. However, although diffusion kinetics determine the maximum production rate in any adsorption-based separation, this aspect has received less attention due to the challenges associated with conducting diffusion measurements. These challenges are exacerbated in the study of shaped adsorbents due to the presence of porosity at different length scales. As a result, adsorbent selection typically relies mainly on adsorption properties at equilibrium, i.e., uptake capacity, selectivity and adsorption enthalpy. In this Perspective, based on an extensive literature review on mass transfer of CO2 in nanoporous adsorbents, we discuss the importance and limitations of measuring diffusion in nanoporous materials, from the powder form to the adsorption bed, considering the nature of the process, i.e., equilibrium-based or kinetic-based separations. By highlighting the lack of and discrepancies between published diffusivity data in the context of CO2 capture, we discuss future challenges and opportunities in studying mass transfer across scales in adsorption-based separations.

Catalytic Upcycling of Polyolefins

The large production volumes of commodity polyolefins (specifically, polyethylene, polypropylene, polystyrene, and poly(vinyl chloride)), in conjunction with their low unit values and multitude of short-term uses, have resulted in a significant and pressing waste management challenge. Only a small fraction of these polyolefins is currently mechanically recycled, with the rest being incinerated, accumulating in landfills, or leaking into the natural environment. Since polyolefins are energy-rich materials, there is considerable interest in recouping some of their chemical value while simultaneously motivating more responsible end-of-life management. An emerging strategy is catalytic depolymerization, in which a portion of the C-C bonds in the polyolefin backbone is broken with the assistance of a catalyst and, in some cases, additional small molecule reagents. When the products are small molecules or materials with higher value in their own right, or as chemical feedstocks, the process is called upcycling. This review summarizes recent progress for four major catalytic upcycling strategies: hydrogenolysis, (hydro)cracking, tandem processes involving metathesis, and selective oxidation. Key considerations include macromolecular reaction mechanisms relative to small molecule mechanisms, catalyst design for macromolecular transformations, and the effect of process conditions on product selectivity. Metrics for describing polyolefin upcycling are critically evaluated, and an outlook for future advances is described.

Phoresis kernel theory for passive and active spheres with nonuniform phoretic mobility

By introducing geometry-based phoresis kernels, we establish a direct connection between the translational and rotational velocities of a phoretic sphere and the distributions of the driving fields or fluxes. The kernels quantify the local contribution of the field or flux to the particle dynamics. The field kernels for both passive and active particles share the same functional form, depending on the position-dependent surface phoretic mobility. For uniform phoretic mobility, the translational field kernel is proportional to the surface normal vector, while the rotational field kernel is zero; thus, a phoretic sphere with uniform phoretic mobility does not rotate. As case studies, we discuss examples of a self-phoretic axisymmetric particle influenced by a globally-driven field gradient, a general scenario for axisymmetric self-phoretic particle and two of its special cases, and a non-axisymmetric active particle.

Ultrasound-mediated spatial and temporal control of engineered cells in vivo

Remote regulation of cells in deep tissue remains a significant challenge. Low-intensity pulsed ultrasound offers promise for in vivo therapies due to its non-invasive nature and precise control. This study uses pulsed ultrasound to control calcium influx in mammalian cells and engineers a therapeutic cellular device responsive to acoustic stimulation in deep tissue without overexpressing calcium channels or gas vesicles. Pulsed ultrasound parameters are established to induce calcium influx in HEK293 cells. Additionally, cells are engineered to express a designed calcium-responsive transcription factor controlling the expression of a selected therapeutic gene, constituting a therapeutic cellular device. The engineered sonogenetic system's functionality is demonstrated in vivo in mice, where an implanted anti-inflammatory cytokine-producing cellular device effectively alleviates acute colitis, as shown by improved colonic morphology and histopathology. This approach provides a powerful tool for precise, localized control of engineered cells in deep tissue, showcasing its potential for targeted therapeutic delivery.

Bridging Macroscopic Diffusion and Microscopic Cavity Escape of Brownian and Active Particles in Irregular Porous Networks

While irregular and geometrically complex pore networks are ubiquitous in nature and industrial processes, there is no universal model describing nanoparticle transport in these environments. 3D super-resolution nanoparticle tracking was employed to study the motion of passive (Brownian) and active (self-propelled) species within complex networks, and universally identified a mechanism involving successive cavity exploration and escape. In all cases, the long-time ensemble-averaged diffusion coefficient was proportional to a quantity involving the characteristic length scale and time scale associated with microscopic cavity exploration and escape (D ∼ r2/ttrap), where the proportionality coefficient reflected the apparent porous network connectivity. For passive nanoparticles, this coefficient was always lower than expected theoretically for a random walk, indicating reduced network accessibility. In contrast, the coefficient for active nanomotors, in the same pore spaces, aligned with the theoretical value, suggesting that active particles navigate "intelligently" in porous environments, consistent with kinetic Monte Carlo simulations in networks with variable pore sizes. These findings elucidate a model of successive cavity exploration and escape for nanoparticle transport in porous networks, where pore accessibility is a function of motive force, providing insights relevant to applications in filtration, controlled release, and beyond.

Understanding Ion Distribution and Diffusion in Solid Polymer Electrolytes

Solid polymer electrolytes (SPEs)─polymer melts with added salts─exhibit ion conduction and high mechanical properties, and are thus promising materials for future energy storage devices. The ion conductivity in an SPE is intricately connected to the salt ion distribution in the polymer matrix. The relationship between ion diffusion and ion distribution in SPEs remains unresolved. Here, we conduct coarse-grained molecular dynamics simulations and establish correlations between ion distribution and transport for a phenomenological SPE model. We propose phase diagrams of SPEs as a function of ion pair size, ion concentration, and the Bjerrum length of the material. A crossover from a discrete ion aggregate to a percolated ion aggregate is demonstrated as a function of ion pair size for low ion concentration in the SPE. The ion diffusion shows a strong correlation with its size, as has been found experimentally. The work provides important design strategies for controlling the ion distribution and enhancing ion conductivity in a polymer matrix.

Perspective on Lignin Conversion Strategies That Enable Next Generation Biorefineries

The valorization of lignin, a currently underutilized component of lignocellulosic biomass, has attracted attention to promote a stable and circular bioeconomy. Successful approaches including thermochemical, biological, and catalytic lignin depolymerization have been demonstrated, enabling opportunities for lignino-refineries and lignocellulosic biorefineries. Although significant progress in lignin valorization has been made, this review describes unexplored opportunities in chemical and biological routes for lignin depolymerization and thereby contributes to economically and environmentally sustainable lignin-utilizing biorefineries. This review also highlights the integration of chemical and biological lignin depolymerization and identifies research gaps while also recommending future directions for scaling processes to establish a lignino-chemical industry.

Micro/nanofabrication of heat management materials for energy-efficient building facades

Advanced building facades, which include windows, walls, and roofs, hold great promise for reducing building energy consumption. In recent decades, the management of heat transfer via electromagnetic radiation between buildings and outdoor environments has emerged as a critical research field aimed at regulating solar irradiation and thermal emission properties. Rapid advancements have led to the widespread utilization of advanced micro/nanofabrication techniques. This review provides the first comprehensive summary of fabrication methods for heat management materials with potential applications in energy-efficient building facades, with a particular emphasis on recent developments in fabrication processing and material property design. These methods include coating, vapor deposition, nanolithography, printing, etching, and electrospinning. Furthermore, we present our perspectives regarding their advantages and disadvantages and our opinions on the opportunities and challenges in this field. This review is expected to expedite future research by providing information on the selection, design, improvement, and development of relevant fabrication techniques for advanced materials with energy-efficient heat management capabilities.

Enthalpic Classification of Water Molecules in Target-Ligand Binding

Water molecules play various roles in target-ligand binding. For example, they can be replaced by the ligand and leave the surface of the binding pocket or stay conserved in the interface and form bridges with the target. While experimental techniques supply target-ligand complex structures at an increasing rate, they often have limitations in the measurement of a detailed water structure. Moreover, measurements of binding thermodynamics cannot distinguish between the different roles of individual water molecules. However, such a distinction and classification of the role of individual water molecules would be key to their application in drug design at atomic resolution. In this study, we investigate a quantitative approach for the description of the role of water molecules during ligand binding. Starting from complete hydration structures of the free and ligand-bound target molecules, binding enthalpy scores are calculated for each water molecule using quantum mechanical calculations. A statistical evaluation showed that the scores can distinguish between conserved and displaced classes of water molecules. The classification system was calibrated and tested on more than 1000 individual water positions. The practical tests of the enthalpic classification included important cases of antiviral drug research on HIV-1 protease inhibitors and the Influenza A ion channel. The methodology of classification is based on open source program packages, Gromacs, Mopac, and MobyWat, freely available to the scientific community.

Bayesian Conavigation: Dynamic Designing of the Material Digital Twins via Active Learning

Scientific advancement is universally based on the dynamic interplay between theoretical insights, modeling, and experimental discoveries. However, this feedback loop is often slow, including delayed community interactions and the gradual integration of experimental data into theoretical frameworks. This challenge is particularly exacerbated in domains dealing with high-dimensional object spaces, such as molecules and complex microstructures. Hence, the integration of theory within automated and autonomous experimental setups, or theory in the loop-automated experiment, is emerging as a crucial objective for accelerating scientific research. The critical aspect is to use not only theory but also on-the-fly theory updates during the experiment. Here, we introduce a method for integrating theory into the loop through Bayesian conavigation of theoretical model space and experimentation. Our approach leverages the concurrent development of surrogate models for both simulation and experimental domains at the rates determined by latencies and costs of experiments and computation, alongside the adjustment of control parameters within theoretical models to minimize epistemic uncertainty over the experimental object spaces. This methodology facilitates the creation of digital twins of material structures, encompassing both the surrogate model of behavior that includes the correlative part and the theoretical model itself. While being demonstrated here within the context of functional responses in ferroelectric materials, our approach holds promise for broader applications, such as the exploration of optical properties in nanoclusters, microstructure-dependent properties in complex materials, and properties of molecular systems.

Recyclable surgical, consumer, and industrial adhesives of poly(α-lipoic acid)

Polymer adhesives play an important role in many medical, consumer, and industrial products. Polymers of α-lipoic acid (αLA) have the potential to fulfill the need for versatile and environmentally friendly adhesives, but their performance is plagued by spontaneous depolymerization. We report a family of stabilized αLA polymer adhesives that can be tailored for a variety of medical or nonmedical uses and sustainably sourced and recycled in a closed-loop manner. Minor changes in monomer composition afforded a pressure-sensitive adhesive that functions well in dry and wet conditions, as well as a structural adhesive with strength equivalent to that of conventional epoxies. αLA surgical superglue successfully sealed murine amniotic sac ruptures, increasing fetal survival from 0 to 100%.

Enhanced catalytic performance through a single-atom preparation approach: a review on ruthenium-based catalysts

The outstanding catalytic properties of single-atom catalysts (SACs) stem from the maximum atom utilization and unique quantum size effects, leading to ever-increasing research interest in SACs in recent years. Ru-based SACs, which have shown excellent catalytic activity and selectivity, have been brought to the frontier of the research field due to their lower cost compared with other noble catalysts. The synthetic approaches for preparing Ru SACs are rather diverse in the open literature, covering a wide range of applications. In this review paper, we attempt to disclose the synthetic approaches for Ru-based SACs developed in the most recent years, such as defect engineering, coordination design, ion exchange, the dipping method, and electrochemical deposition etc., and discuss their representative applications in both electrochemical and organic reaction fields, with typical application examples given of: Li-CO2 batteries, N2 reduction, water splitting and oxidation of benzyl alcohols. The mechanisms behind their enhanced catalytic performance are discussed and their structure-property relationships are revealed in this review. Finally, future prospects and remaining unsolved issues with Ru SACs are also discussed so that a roadmap for the further development of Ru SACs is established.

Evaluation of the release kinetics of hydrophilic and lipophilic compounds from lipid-polymer hybrid nanoparticles

In disease treatment, maintaining therapeutic drug concentrations often requires multiple doses. Lipid/polymer hybrid nanoparticles (LPHNPs) offer a promising solution by facilitating sustained drug delivery within therapeutic ranges. Here, we synthesized poly(lactic-co-glycolic acid) (PLGA) nanoparticles coated with soy lecithin using nanoprecipitation and self-assembly techniques. These nanoparticles were incorporated into gelatin aerogels to ensure uniform distribution and increase the concentration. Our study focused on understanding the release kinetics of hydrophilic (gallic acid) and lipophilic (quercetin) compounds from this system. Nanoparticles exhibited hydrodynamic diameters of 100 ± 15 nm (empty), 153 ± 33 nm (gallic acid-loaded), and 149 ± 21 nm (quercetin-loaded), with encapsulation efficiencies of 90 ± 5% and 70 ± 10% respectively. Gallic acid release followed the Korsmeyer-Peppas kinetics model (n = 1.01), while quercetin showed first-order kinetics. Notably, encapsulated compounds demonstrated delayed release compared to free compounds in gelatin aerogels, illustrating LPHNPs' ability to modulate release profiles independent of the compound type. This study underscores the potential of LPHNPs in optimizing drug delivery strategies for enhanced therapeutic outcomes.

Insights into the nucleation and growth of BiOCl nanoparticles by in situ X-ray pair distribution function analysis and in situ liquid cell TEM

The synthesis of bismuth oxyhalides as defined nanostructures is hindered by their fast nucleation and growth in aqueous solutions. Using our recently developed single-source precursor, the formation of bismuth oxychloride in such solutions can be slowed significantly. As reported herein, this advance enables BiOCl formation to be investigated by in situ X-ray total scattering and in situ liquid cell transmission electron microscopy. In situ pair distribution function analysis of X-ray total scattering data reveals the local order of atomic structures throughout the synthesis, while in situ liquid cell transmission electron microscopy allows for tracking the growth of individual nanoparticles. Through this work, the precursor complex is shown to give rise to BiOCl upon heating in solution without the observation of structurally distinct intermediates. The emerging nanoparticles have a widened interlayer spacing, which moderately decreases as the particles grow. Mechanistic insights into the formation of bismuth oxyhalide nanoparticles, including the absence of distinct intermediates within the available time resolution, will help facilitate future design of controlled BiOX nanostructures.

Programming mammalian cell behaviors by physical cues

In recent decades, the field of synthetic biology has witnessed remarkable progress, driving advances in both research and practical applications. One pivotal area of development involves the design of transgene switches capable of precisely regulating specified outputs and controlling cell behaviors in response to physical cues, which encompass light, magnetic fields, temperature, mechanical forces, ultrasound, and electricity. In this review, we delve into the cutting-edge progress made in the field of physically controlled protein expression in engineered mammalian cells, exploring the diverse genetic tools and synthetic strategies available for engineering targeting cells to sense these physical cues and generate the desired outputs accordingly. We discuss the precision and efficiency limitations inherent in these tools, while also highlighting their immense potential for therapeutic applications.

Exosome Loaded Protein Hydrogel for Enhanced Gelation Kinetics and Wound Healing

Exosomes are being increasingly explored in biomedical research for wound healing applications. Exosomes can improve blood circulation and endocrine signaling, resulting in enhanced cell regeneration. However, exosome treatments suffer from low retention and bioavailability of exosomes at the wound site. Hydrogels are a popular tool for drug delivery due to their ability to encapsulate drugs in their network and allow for targeted release. Recently, hydrogels have proven to be an effective method to provide increased rates of wound healing when combined with exosomes that can be applied noninvasively. We have designed a series of single-domain protein-based hydrogels capable of physical cross-linking and upper critical solution temperature (UCST) behavior. Hydrogel variant Q5, previously designed with improved UCST behavior and a significantly enhanced gelation rate, is selected as a candidate for encapsulation release of exosomes dubbed Q5Exo. Q5Exo exhibits low critical gelation times and significant decreases in wound healing times in a diabetic mouse wound model showing promise as an exosome-based drug delivery tool and for future hybrid, noninvasive protein-exosome design.

Ultraselective Macrocycle Membranes for Pharmaceutical Ingredients Separation in Organic Solvents

Separations are core processes in the chemical and pharmaceutical industries. Several steps of fractionation and purification of multicomponent mixtures are required. Membrane technology can operate at fair temperatures, saving energy and processing sensitive compounds. However, breakthroughs require high stability and selectivity beyond those available today. Here, we propose membranes constituted by fully crosslinked crown ethers using interfacial polymerization. The 24 nm-thick nanofilms on robust porous supports exhibit up to 90% higher selectivity than commercially available membranes, with a 90% increase in solvent permeance. The membranes are tested with a complex mixture of structurally diverse solutes containing active pharmaceutical ingredients. The membranes are effective for the total retention and concentration of active pharmaceutical ingredients with molecular weights around 800 g mol-1. The ability to distinguish between smaller molecules in the range between 100 and 370 g mol-1 is confirmed with high separation factors, which could provide a significant advance for the pharmaceutical industry.

Depletion Flocculation of High Internal Phase Pickering Emulsion Inks: A Colloidal Engineering Approach to Develop 3D Printed Porous Scaffolds with Tunable Bioactive Delivery

Flocculation is a type of aggregation where the surfaces of approaching droplets are still at distances no closer than a few nanometers while still remaining in close proximity. In a high internal-phase oil-in-water (O/W) emulsion, the state of flocculation affects the bulk flow behavior and viscoelasticity, which can consequently control the three-dimensional (3D)-printing process and printing performance. Herein, we present the assembly of O/W Pickering high-internal-phase emulsions (Pickering-HIPEs) as printing inks and demonstrate how depletion flocculation in such Pickering-HIPE inks can be used as a facile colloidal engineering approach to tailor a porous 3D structure suitable for drug delivery. Pickering-HIPEs were prepared using different levels of cellulose nanocrystals (CNCs), co-stabilized using "raw" submicrometer-sized sustainable particles from a biomass-processing byproduct. In the presence of this sustainable particle, the higher CNC contents facilitated particle-induced depletion flocculation, which led to the formation of a mechanically robust gel-like ink system. Nonetheless, the presence of adsorbed particles on the surface of droplets ensured their stability against coalescence, even in such a highly aggregated system. The gel structures resulting from the depletion phenomenon enabled the creation of high-performance printed objects with tunable porosity, which can be precisely controlled at two distinct levels: first, by introducing voids within the internal structure of filaments, and second, by generating cavities (pore structures) through the elimination of the water phase. In addition to printing efficacy, the HIPEs could be applied for curcumin delivery, and in vitro release kinetics demonstrated that the porous 3D scaffolds engineered for the first time using depletion-flocculated HIPE inks played an important role in 3D scaffold disintegration and curcumin release. Thus, this study offers a unique colloidal engineering approach of using depletion flocculation to template 3D printing of sustainable inks to generate next-generation porous scaffolds for personalized drug deliveries.

Lattice-Cluster-Theory-Informed Cross-Fractionation Chromatography Revealing Degree of Crystallinity of Single Macromolecular Species

The relationship between macromolecular architecture and crystallization properties is a relevant research topic in polymer science and technology. The average degree of crystallinity of disperse polymers is a well-studied quantity and is accessible by various experimental methods. However, how the different macromolecular species contribute to the degree of crystallinity and, in particular, the relationship between a certain macromolecular architecture and the degree of crystallinity are not accessible today, neither experimentally nor theoretically. Therefore, in this work, a lattice cluster theory (LCT)-informed cross-fractionation chromatography (CFC) approach is developed to access the degree of crystallinity of single and nonlinear macromolecular species crystallizing from solution. The method entangles high-throughput experimental data from CFC with the LCT for semicrystalline polymers to predict the degree of crystallinity of polymer species with different molecular weights and branching. The approach is applied to a linear low-density polyethylene (ethylene/1-octene copolymer) and a high-density polyethylene, which have specific and different bivariate distributions. The degree of crystallinity of individual macromolecular species of these polymer samples is calculated, and the predicted average degree of crystallinity is compared with experimental measurements, thus successfully validating the approach. Furthermore, the average segment length between branches is introduced as a characteristic molecular feature of branched polyethylene, and its relationship with the degree of crystallinity of certain species is established.

Porous Polymeric Electrodes for Electrochemical Carbon Dioxide Capture

Carbon capture is a promising technology to mitigate greenhouse gas emissions to achieve net carbon neutrality. Electro-swing reactive adsorption has emerged as an attractive approach for sustainable decarbonization. However, current electrodes with limited gas transport present a major barrier that hinders their practical implementation. Herein, porous polymeric electrodes are developed to effectively enhance CO2 transport without the need for additional gas diffusion conduits. Such all-in-one porous electrodes also enable more accessible redox active sites (e.g., quinones) for CO2 sorption, leading to an increased materials utilization efficiency of ≈90%. A continuous flow-through carbon capture and release operation with high Faradaic efficiency and excellent stability under practical working conditions is further demonstrated. Together with low cost and robust mechanical properties, the as-developed porous polymeric electrodes highlight the potential to advance the future implementation of electrochemical separation technologies.

Magnetic Nanoparticles: A Comprehensive Review from Synthesis to Biomedical Frontiers

Nanotechnology has opened new doors of exploration, particularly in materials science and healthcare. Magnetic nanoparticles (MNP), the tiny magnets, because of their various properties, have the potential to bring about radical changes in the field of medicine. The distinctive surface chemistry, nontoxicity, biocompatibility, and, in particular, the inducible magnetic moment of magnetic materials has attracted a great deal of interest in morphological structures from a variety of scientific domains. This review presents a concise overview of MNPs and their crucial properties and synthesis routes. It also aims to highlight the continuous synthesis methods available for MNP production. In recent years, the use of computational methods for understanding the behavior of nanoparticles has been on the rise. Thus, we also discuss the numerical models developed to understand how magnetic nanoparticles can be used in magnetic hyperthermia and targeting the Circle of Wilis. With the increasing use of MNPs in biomedical applications, it becomes necessary to understand the mechanisms of toxicity, which are elucidated in this review. The review focuses on the biomedical applications of MNPs in drug delivery, theranostics, and MRI contrasting agents. We anticipate that this article will broaden the perspective on magnetic nanoparticles and help to understand their functionality and applicability better.

Small-Angle Scattering Indicates Equilibrium Instead of Metastable Capillary Condensation in SBA-15 Mesoporous Silica

Questions about the origin of the adsorption/desorption hysteresis in mesoporous materials are as old as sorption experiments themselves. The historical conception that underlines most existing methods to extract pore size distributions from sorption data assumes that adsorption is a metastable process and that desorption takes place at thermodynamic equilibrium. In this work, we measure nitrogen and argon sorption on a series of 14 SBA-15 ordered mesoporous silicas and use small-angle X-ray scattering to independently determine their pore sizes. We find that capillary condensation systematically occurs close to thermodynamic equilibrium according to a Derjaguin-Broekhoff-de Boer calculation. Our analysis suggests that many earlier works have significantly underestimated the actual pore size in SBA-15 materials. It also highlights the critical role of the reference isotherm used to calibrate the fluid-solid interaction in the models.

Membranes Based on Aminated Graphene Oxide with High Selectivity Toward Organic Substances

In this work, membranes based on graphene oxide, modified with oleylamine, have been prepared by a simple wet chemistry protocol without the use of complex equipment, elevated temperature, and additional reagents. The membrane material was characterized by a set of physicochemical methods: thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffractometry, and X-ray photoelectron spectroscopy. The prepared membranes are stable in both aqueous and organic media. The membranes have a high flux for organic substances and do not permeate water at room temperature and atmospheric pressure. The selectivity of the membranes toward organic substances increases with their thickness. The highest flux among the tested organic liquids is registered for methanol. The membranes have high selectivity toward ethanol/1-butanol and acetone/1-butanol pairs, which opens up the possibility of separating actual industrial mixtures. The membrane retains 90% of methylene blue from the alcohol solution. Our work expands the possibilities of using modified GO-based membranes in purification and filtration technologies.

Biomaterial-Based Sustained-Release Drug Formulations for Localized Cancer Immunotherapy

Cancer immunotherapy has revolutionized clinical cancer treatments by taking advantage of the immune system to selectively and effectively target and kill cancer cells. However, clinical cancer immunotherapy treatments often have limited efficacy and/or present severe adverse effects associated primarily with their systemic administration. Localized immunotherapy has emerged to overcome these limitations by directly targeting accessible tumors via local administration, reducing potential systemic drug distribution that hampers drug efficacy and safety. Sustained-release formulations can prolong drug activity at target sites, which maximizes the benefits of localized immunotherapy to increase the therapeutic window using smaller dosages than those used for systemic injection, avoiding complications of frequent dosing. The performance of sustained-release formulations for localized cancer immunotherapy has been validated preclinically using various implantable and injectable scaffold platforms. This review introduces the sustained-release formulations developed for localized cancer immunotherapy and highlights their biomaterial-based platforms for representative classes, including inorganic scaffolds, natural hydrogels, synthetic hydrogels, and microneedle patches. The design rationale and other considerations are summarized for further development of biomaterials for the construction of optimal sustained-release formulations.

Tissue-scale in vitro epithelial wrinkling and wrinkle-to-fold transition

Although epithelial folding is commonly studied using in vivo animal models, such models exhibit critical limitations in terms of real-time observation and independent control of experimental parameters. Here, we develop a tissue-scale in vitro epithelial bilayer folding model that incorporates an epithelium and extracellular matrix (ECM) hydrogel, thereby emulating various folding structures found in in vivo epithelial tissue. Beyond mere folding, our in vitro model realizes a hierarchical transition in the epithelial bilayer, shifting from periodic wrinkles to a single deep fold under compression. Experimental and theoretical investigations of the in vitro model imply that both the strain-stiffening of epithelium and the poroelasticity of ECM influence the folded structures of epithelial tissue. The proposed in vitro model will aid in investigating the underlying mechanism of tissue-scale in vivo epithelial folding relevant to developmental biology and tissue engineering.

A Comprehensive Review of the Strategies to Reduce Retinoid-Induced Skin Irritation in Topical Formulation

Currently, retinoids are known for their abundant benefits to skin health, ranging from reducing signs of aging and decreasing hyperpigmentation to treating acne. However, it cannot be denied that there are various side effects associated with the use of retinoids on the skin, one of which is irritation. Several approaches can be employed to minimize the irritation caused by retinoids. This review article discusses topical retinoid formulation technology strategies to reduce skin irritation effects. The methodology used in this study is a literature review of 21 reference journals. The sources used in compiling this review are from PubMed, Scopus, ScienceDirect, and MEDLINE. The findings obtained indicate that the following methods can be used to lessen retinoid-induced irritation in topical formulations: developing drug delivery systems in the formulation, such as encapsulating retinoids, transforming retinoids into nanoparticles, forming complexes (e.g., with cyclodextrin), and binding retinoids with carriers (e.g., polymers, NLC, SLN), adding ingredients with anti-irritation activity, skin barrier improvement, and increased skin hydration to retinoid formulations (e.g., combinations of glucosamine, trehalose, ectoine, sucralfate, omega-9, and 4-t-butylcyclohexanol, addition of ethanolic bark extract of Alstonia scholaris R. Br).

Proteolytic Regulation in the Biosynthesis of Natural Product Via a ClpP Protease System

Protein degradation is a tightly regulated biological process that maintains bacterial proteostasis. ClpPs are a highly conserved family of serine proteases that associate with the AAA + ATPase (an ATPase associated with diverse cellular activities) to degrade protein substrates. Identification and biochemical characterization of protein substrates for the AAA + ATPase-dependent ClpP degradation systems are considered essential for gaining an understanding of the molecular operation of the complex ClpP degradation machinery. Consequently, expanding the repertoire of protein substrates that can be degraded in vitro and within bacterial cells is necessary. Here, we report that AAA + ATPase-ClpP proteolytic complexes promote degradation of the secondary metabolite surfactin synthetases SrfAA, SrfAB, and SrfAC in Bacillus subtilis. On the basis of in vitro and in-cell studies coupled with activity-based protein profiling of nonribosomal peptide synthetases, we showed that SrfAC is targeted to the ClpC-ClpP proteolytic complex, whereas SrfAA is hydrolyzed not only by the ClpC-ClpP proteolytic complex but also by different ClpP proteolytic complexes. Furthermore, SrfAB does not appear to be a substrate for the ClpC-ClpP proteolytic complex, thereby implying that other ClpP proteolytic complexes are involved in the degradation of this surfactin synthetase. Natural product biosynthesis is regulated by the AAA + ATPase-ClpP degradation system, indicating that protein degradation plays a role in the regulatory stages of biosynthesis. However, few studies have examined the regulation of protein degradation levels. Furthermore, SrfAA, SrfAB, and SrfAC were identified as protein substrates for AAA + ATPase-ClpP degradation systems, thereby contributing to a better understanding of the complex ClpP degradation machinery.

Active Stratification of Colloidal Mixtures for Asymmetric Multilayers

Stratified films offer high performance and multifunctionality, yet achieving fully stratified films remains a challenge. The layer-by-layer method, involving the sequential deposition of each layer, has been commonly utilized for stratified film fabrication. However, this approach is time-consuming, labor-intensive, and prone to leaving defects within the film. Alternatively, the self-stratification process exploiting a drying binary colloidal mixture is intensively developed recently, but it relies on strict operating conditions, typically yielding a heterogeneous interlayer. In this study, an active interfacial stratification process for creating completely stratified nanoparticle (NP) films is introduced. The technique leverages NPs with varying interfacial activity at the air-water interface. With the help of depletion pressure, the lateral compression of NP mixtures at the interface induces individual desorption of less interfacial active NPs into the subphase, while more interfacial active NPs remain at the interface. This simple compression leads to nearly perfect stratified NP films with controllability, universality, and scalability. Combined with a solvent annealing process, the active stratification process enables the fabrication of stratified films comprising a polymeric layer atop a NP layer. This work provides insightful implications for designing drug encapsulation and controlled release, as well as manufacturing transparent and flexible electrodes.

Softening implantable bioelectronics: Material designs, applications, and future directions

Implantable bioelectronics, integrated directly within the body, represent a potent biomedical solution for monitoring and treating a range of medical conditions, including chronic diseases, neural disorders, and cardiac conditions, through personalized medical interventions. Nevertheless, contemporary implantable bioelectronics rely heavily on rigid materials (e.g., inorganic materials and metals), leading to inflammatory responses and tissue damage due to a mechanical mismatch with biological tissues. Recently, soft electronics with mechanical properties comparable to those of biological tissues have been introduced to alleviate fatal immune responses and improve tissue conformity. Despite their myriad advantages, substantial challenges persist in surgical handling and precise positioning due to their high compliance. To surmount these obstacles, softening implantable bioelectronics has garnered significant attention as it embraces the benefits of both rigid and soft bioelectronics. These devices are rigid for easy standalone implantation, transitioning to a soft state in vivo in response to environmental stimuli, which effectively overcomes functional/biological problems inherent in the static mechanical properties of conventional implants. This article reviews recent research and development in softening materials and designs for implantable bioelectronics. Examples featuring tissue-penetrating and conformal softening devices highlight the promising potential of these approaches in biomedical applications. A concluding section delves into current challenges and outlines future directions for softening implantable device technologies, underscoring their pivotal role in propelling the evolution of next-generation bioelectronics.

Assessment of the Potential of Electrochemical Steps in Direct Air Capture through Techno-Economic Analysis

Direct air capture (DAC) technologies are proposed to reduce the atmospheric CO2 concentration to mitigate climate change and simultaneously provide carbon as a feedstock independent of fossil resources. The currently high energy demand and cost of DAC technologies are challenging and could limit the significance of DAC processes. The present work estimates the potential energy demand and the levelized cost of capture (LCOC) of liquid solvent absorption and solid adsorption DAC processes in the long term. A consistent framework is applied to compare nonelectrochemical to electrochemical DAC processes and estimate the LCOC depending on the electricity price. We determine the equivalent cell voltage needed for the electrochemical steps to achieve comparable or lower energy demand than nonelectrochemical processes. The capital expenses (CapEx) of the electrochemical steps are estimated using analogies to processes that are similar in function. The results are calculated for a range of initial data of CapEx and energy demand to include uncertainties in the data.