Light-Driven Green-Fabricated Artificial Intelligence-Enabled Micro/Nanorobots for Multimodal Phototherapeutic Management of Bladder Cancer

Combination therapy based on precise phototherapies combined with immune modulation provides successful antitumor effects. In this study, a combination therapy is designed based on phototactic, photosynthetic, and phototherapeutic Chlamydomonas Reinhardtii (CHL)-glycol chitosan (GCS)-polypyrrole (PPy) nanoparticle (NP)-enhanced immunity combined with the tumor microenvironment turnover of cytotoxic T cells and M1/M2 macrophages, which is based on photothermal GCS-PPy NPs decorated onto the phototactic and photosynthetic CHL. Phototherapy based on CHL-GCS-PPy NPs alleviates hypoxia and modulates the tumor immune microenvironment, which induces tumor cell death. In particular, the precise antitumor immune response and potent immune memory induced by combining self-navigated phototherapies significantly alleviate the progression of bladder cancer in C57BL/6 mice and effectively inhibit bladder tumor growth. Furthermore, they also potentially prevent tumor recurrence, which provides a promising therapeutic strategy for clinical tumor therapy.

Algae: the game-changers in biohydrogen sector

Biohydrogen (H2) is an efficient form of renewable energy generated from various biological organisms. Specifically, primitive plants such as algae which are photosynthetic organisms can produce several commercial products, including biofuels due to their simple form, short life span, efficient photosynthetic capacity, and ability to grow in non-potable water sources. But these algae are often neglected and considered waste. Several studies have revealed the importance and role of algal species in generating biofuels, especially biohydrogen. Considerable research has been conducted in order to understand hydrogen production from algal sources. This review emphasizes the photolysis of water-based hydrogen production in algae apart from the metabolites fermentation process. The influence of physico-chemical factors, including oxygen scavengers, nanoparticles, and hydrogenases, was highlighted in this review to enhance H2 production from algal species. Also, several algal species used for hydrogen production are summarized in detail. Overall, this review intends to summarize the developments in hydrogen production from algal species keeping in view of excellent prospects. This knowledge certainly would provide a good opportunity for the industrial production of hydrogen using algal species, which is one of the most concerned areas in the energy sector.

Synergistic enhancement of pulsed light-induced H2 photoproduction in Chlamydomonas cells by optimal sulfite concentration and light waveform

Pulsed light illumination stands out as a noteworthy technique for photosynthetic H2 production, playing a crucial role in eliminating O2 and activating hydrogenase enzymes. However, further improvements are essential to make H2 photoproduction suitable for future commercial applications. In our study, we observed a distinct enhancement in pulsed light-induced H2 photoproduction in the unicellular green alga Chlamydomonas reinhardtii when treated with the optimal concentration of the mild O2 scavenger Na2SO3. This improvement was a result of reduced O2 content, increased hydrogenase enzyme activity, and suppressed H2-uptake activity. Furthermore, our findings indicate that exposing Na2SO3-treated C. reinhardtii to optimal light waveform continues to significantly boost pulsed light-induced H2 photoproduction, attributed to the alleviation of impaired photosystem II activity. Altogether, the combined application of optimal sulfite concentration and light waveform effectively enhances pulsed light-induced photosynthetic H2 production in the green alga C. reinhardtii.

Temperature modulated sustainable on/off photosynthesis switching of microalgae towards hydrogen evolution

Despite great progress in the active interfacing between various abiotic materials and living organisms, the development of a smart polymer matrix with modulated functionality of algae towards the application of green bioenergy is still rare. Herein, we design a thermally sensitive poly(N-isopropylacrylamide)-co-poly(butyl acrylate) with an LCST (ca. 25 °C) as a chassis, which could co-assemble with algal cells based on hydrophobic interaction to generate a new type of robust hybrid hydrogel living material. By modulating the temperature to 30 °C, the volume of the polymer matrix is shrunk by 9 times, which allows the formation of physical shading and metabolism changing of the algae, and then triggers the functionality switching of the algae from photosynthetic oxygen production to hydrogen production. By contrast, by decreasing the temperature to 20 °C, the hybrid living materials go into a sol state where the algae behave normally with photosynthetic oxygen production. In particular, due to the proliferation of the algae in living materials, a long-term and exponential enhancement in the amount of hydrogen produced is achieved. Overall, it is anticipated that our investigations could provide a new paradigm for the development of polymer/living organism-based hybrid living materials with synergistic functionality boosting green biomanufacturing.

Effects and mechanisms of decabromodiphenyl ethane on Chlorella sorokiniana: Transcriptomics, proteins and fatty acid production

Decabromodiphenyl ethane is a novel brominated flame retardant, that has always been dissolved in organic solvents to explore its activities on aquatic organisms. In this study, the influences of decabromodiphenyl ethane on the microalga Chlorella sorokiniana (C. sorokiniana) were studied, and three microalgae treatments, including decabromodiphenyl ethane dissolved in dimethyl sulfoxide solvent (DBDPE treatment), dimethyl sulfoxide alone (control II) or untreated (control I) were used in the experiment, respectively. The results showed that the growth of C. sorokiniana was remarkably enhanced in the DBDPE treatment compared with the control I and II groups. Conjoint analysis of transcriptomics and quantitative proteome displayed that the upregulated differentially expressed genes and proteins of DBDPE:control I were enriched in 6 pathways, and downregulated genes/proteins of DBDPE:control I were enriched in 3 pathways. The upregulated differentially expressed genes and proteins of DBDPE:control II were enriched in 4 pathways, and downregulated genes/proteins of DBDPE:control II were enriched in 6 pathways. In addition, decabromodiphenyl ethane changed the fatty acid concentration in C. sorokiniana cells. The activities of superoxide dismutase were enhanced when C. sorokiniana were treated by decabromodiphenyl ethane. The data highlighted that the mRNA and protein expression relating to the fatty acid production, of C. sorokiniana were significantly affected by decabromodiphenyl ethane, and decabromodiphenyl ethane pollution changed the physiological metabolism of microalgae and had harmful effects on natural environments.

Chemical Flocculation-Based Green Algae Materials for Photobiological Hydrogen Production

Photobiological hydrogen production is among the most promising ways toward the mass production of hydrogen energy. The use of green algal aggregates to produce photobiological hydrogen has attracted much attention because it overcomes the limitations of sulfur deprivation and oxygen scavengers. However, the current preparation of green algal aggregates that are capable of hydrogen production is time-consuming and laborious, leading to a difficulty in large-scale applications. Here, we demonstrated that the chemical flocculation of green algae is able to generate aggregates for photobiological hydrogen production. We find that Chlorella pyrenoidosa can directly form aggregates in the original liquid cultures by a commercial chemical flocculant, cationic etherified starch, thereby achieving sustainable hydrogen production for 11 days under continuous light irradiation, and the average rate of photobiological production reaches 0.37 μmol H₂ (mg chlorophyll·h)^-1. This research provides a feasible approach for preparing a low-cost photobiological hydrogen production system helping to realize carbon neutrality.

Hydrogen production technologies - Membrane based separation, storage and challenges

The production of hydrogen, its separation, and storage for use as a primary source of energy is an important component of the green energy economy of the world. Hydrogen is a potential non-carbon-based energy source, which is gradually replacing the dependency on fossil fuels. It is anticipated that as the alternative fuel since hydrogen can be produced from green and clean sources. The evolution of hydrogen from renewable and non-renewable sources by various technologies has now gained tremendous research and industrial interest. The most appropriate methods for hydrogen generation involve the direct conversion of solar energy, exploitation of solar and wind energy for the electrolysis of water, besides conversion of fuel and biomass. To produce cleaner hydrogen and its separation from the chemical impurities is crucial and several methods including photobiological, photoelectrochemical, electrochemical, photocatalytic, thermochemical, thermolysis, and steam gasification have been used. The diverse types of membranes along with the pressure gas swing adsorption technique is another technique used to separate hydrogen, but the storage of hydrogen in an inexpensive, safe, compact, and environmentally friendly manner is one of the major concerns contributing to the country's economy. Apart from the countless advantages, storage and handling of hydrogen is a serious concern. Owing to its high inflammability, enough safety measures should be adopted during its production and storage as a fuel. It is necessary to provide information regarding the production technologies, storage, and separation methods of hydrogen and the present review addresses these issues.

Advanced microalgae-based renewable biohydrogen production systems: A review

The reliance of fossil fuel for industrial and energy sectors has resulted in its depletion. Therefore, enormous efforts have been considered to move-out from fossil fuels to renewable energy sources based industrial process developments. Recently, biohydrogen (bio-H₂) has been recognised as a clean source of fuel with high-energy efficiency, which can be produced via different routes. Among them, biological fermentation processes are highly recommended due to eco-friendly and economically viable approaches compared to that of thermochemical processes. However, the low H₂ yield and high production cost are major bottlenecks for commercial scale operations. Thus, this review proposed an integrated microalgae-based H₂ production process, which will provides a possible route for commercialization in near future. Furthermore, process integration to improve efficiency and implementation of advanced strategies for the enhancement of bio-H₂ production, economic viability, and future research needs are discussed.

Single-Cell Nanoencapsulation: From Passive to Active Shells

Single-cell nanoencapsulation is an emerging field in cell-surface engineering, emphasizing the protection of living cells against external harmful stresses in vitro and in vivo. Inspired by the cryptobiotic state found in nature, cell-in-shell structures are formed, which are called artificial spores and which show suppression or retardation in cell growth and division and enhanced cell survival under harsh conditions. The property requirements of the shells suggested for realization of artificial spores, such as durability, permselectivity, degradability, and functionalizability, are demonstrated with various cytocompatible materials and processes. The first-generation shells in single-cell nanoencapsulation are passive in the operation mode, and do not biochemically regulate the cellular metabolism or activities. Recent advances indicate that the field has shifted further toward the formation of active shells. Such shells are intimately involved in the regulation and manipulation of biological processes. Not only endowing the cells with new properties that they do not possess in their native forms, active shells also regulate cellular metabolism and/or rewire biological pathways. Recent developments in shell formation for microbial and mammalian cells are discussed and an outlook on the field is given.

Mechanistic insights into pH-dependent H2 photoproduction in bisulfite-treated Chlamydomonas cells

BACKGROUND

Bisulfite addition is an important H₂ photoproduction strategy that removes O₂ and activates hydrogenase. The pH values of cell cultures can change the ratio of bisulfite to sulfite, which may affect H₂ photoproduction. However, little is known regarding the pH effect of bisulfite addition on H₂ photoproduction and relevant underlying mechanism.

RESULTS

Here, changes in H₂ photoproduction with different initial extracellular pH values showed a parabolic distribution and a pH of 8.0 is an optimal value for H₂ photoproduction in Chlamydomonas reinhardtii cells treated with bisulfite. Compared to the growth pH (pH 7.3), increased photoproduction of H₂ at this optimal pH was primarily caused by a relatively high residual activity of photosystem II (PSII), which provides a relatively plentiful source of electrons for H₂ photoproduction. Such increased H₂ photoproduction was most likely a result of decreased the ratio of bisulfite to sulfite, consistent with the result that the toxicity of bisulfite on PSII was much more than that of sulfite. This possibility was corroborated by the result that treatment with a combination of 7 mM bisulfite and 6 mM sulfite further enhanced H₂ photoproduction compared with 13 mM bisulfite alone.

CONCLUSIONS

Collectively, our findings provide novel mechanistic insights into pH-dependent H₂ photoproduction in C. reinhardtii cells treated with bisulfite, and demonstrate that sulfite addition is another important strategy for H₂ photoproduction, just like bisulfite addition.

A Stepwise NaHSO3 Addition Mode Greatly Improves H2 Photoproduction in Chlamydomonas reinhardtii

NaHSO₃ addition greatly increases the yield of H₂ photoproduction in a unicellular green alga Chlamydomonas reinhardtii through removing O₂ and activating hydrogenase but significantly impairs the activity of PSII, an electron source for H₂ photoproduction. Here, a stepwise addition mode of total 13 mM NaHSO₃, an optimal concentration for H₂ photoproduction of C. reinhardtii identified in a previous one step addition method, significantly improved H₂ photoproduction. Such improvement was believed to be the result of increased residual PSII activity in an anaerobic background, but was at least independent of two alternative electron sinks for H₂ photoproduction, cyclic electron transport around PSI and CO₂ assimilation. Based on the above results, we propose that increased residual PSII activity in an anaerobic environment is an efficient strategy to enhance H₂ photoproduction in C. reinhardtii, and the stepwise NaHSO₃ addition mode is a case study in the strategy.