Albumin is derived from plasma and it is the most abundant protein in plasma, which is an ideal material for the preparation of nanoparticles because of its good biocompatibility, noncytotoxicity, nonimmunogenicity, biodegradability, and so on. Besides, albumin can enhance the targeting of drugs, reduce the toxicity of free drugs, and enhance the water solubility of hydrophobic drugs, etc. Drug delivery systems based on albumin nanoparticles are widely used in the medical field. At present, the main methods of preparing albumin nanoparticles are desolvation, self-assembly, thermal gelation, spray-drying, double emulsification, emulsification, Nab-technology, pH coacervation, and so on. Due to the differences of principle and preparation conditions, these methods show different advantages and disadvantages. This review systematically summarizes the latest research progress of albumin nanoparticles about its methods of preparation in past five years, and it also introduces the latest applications in cancer therapy, existing difficulties. Thus, this review can fill the two gaps that few articles focus comprehensively on the application of albumin nanoparticles in tumor therapy and no article clearly points out the difficulties faced in current research of albumin nanoparticles.

Although keratins are robust in nature, hydrogels producing their extracts exhibit poor mechanical properties due to the complicated composition and ineffective self-assembly. Here we report a bioinspired strategy to fabricate robust keratin hydrogels based on mechanism study through recombinant proteins. Homotypic and heterotypic self-assembly of selected type I and type II keratins in different combinations was conducted to identify crucial domain structures for the process, their kinetics, and relationship with the mechanical strength of hydrogels. Segments with best performance were isolated and used to construct novel assembling units. The new design outperformed combinations of native proteins in mechanical properties and in biomedical applications such as controlled drug release and skin regeneration. Our approach not only elucidated the critical structural domains and underlying mechanisms for keratin selfassembly but also opens an avenue toward the rational design of robust keratin hydrogels for biomedical applications.

H uman s erum a lbumin (HSA) is a highly water-soluble protein with 67% alpha-helix content and three distinct domains (I, II, and III). HSA offers a great promise in drug delivery with enhanced permeability and retention effect. But it is hindered by protein denaturation during drug entrapment or conjugation that result in distinct cellular transport pathways and reduction of biological activities. Here we report using a protein design approach named r everse- QTY (rQTY) code to convert specific hydrophilic alpha-helices to hydrophobic to alpha-helices. The designed HSA undergo self-assembly of well-ordered nanoparticles with highly biological actives. The hydrophilic amino acids, asparagine (N), glutamine (Q), threonine (T), and tyrosine (Y) in the helical B-subdomains of HSA were systematically replaced by hydrophobic leucine (L), valine (V), and phenylalanine (F). HSA rQTY nanoparticles exhibited efficient cellular internalization through the cell membrane albumin binding protein GP60, or SPARC ( s ecreted p rotein, a cidic and r ich in c ysteine)-mediated pathways. The designed HSA rQTY variants displayed superior biological activities including: i) encapsulation of drug doxorubicin, ii) receptor-mediated cellular transport, iii) tumor cell targeting, and iv) antitumor efficiency compare to denatured HSA nanoparticles. HSA rQTY nanoparticles provided superior tumor targeting and antitumor therapeutic effects compared to the albumin nanoparticles fabricated by antisolvent precipitation method. We believe that the rQTY code is a robust platform for specific hydrophobic modification of functional hydrophilic proteins with clear-defined binding interfaces.

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Botrytis cinerea is one of the most destructive fungal pathogens causing tremendous losses in fresh fruit or vegetables. 3-Methylthio-1-propanol (3-MP) is a naturally occurring food-borne sulfide, which is mainly used to increase the flavor in food. However, the potential application of 3-MP in the postharvest phase to manage fruit fungal diseases has not been explored. In this study, the antifungal activity of 3-MP against B. cinerea was evaluated, and the possible mechanism involved was explored. In vitro 3-MP treatment could effectively inhibit the mycelial growth, spore germination, and germ tube elongation of B. cinerea. 3-MP also impaired the spore viability and membrane integrity of B. cinerea as well as increased the leakage of nucleic acids, proteins, and malondialdehyde (MDA) in B. cinerea. In vivo 3-MP fumigation treatment inhibited the infection of B. cinerea on tomato fruits. Also, the fruits with 3-MP fumigation treatment exhibited higher antioxidant enzyme activity, lower MDA content, and a significant delay of induction of the expression of most of the stress-related genes when compared to the control group. Moreover, a cytotoxicity evaluation revealed that 3-MP had no toxicity to normal cells in a certain concentration range. Collectively, our research results will provide evidence for the development of food-borne sulfide 3-MP as a fungicide in food and agriculture and will provide an important reference for the formulation of B. cinerea biocontrol strategies.

Albumin is derived from blood plasma and is the most abundant protein in blood plasma, which has good mechanical properties, biocompatibility and degradability, so albumin is an ideal biomaterial for biomedical applications, and drug-carriers based on albumin can better reduce the cytotoxicity of drug. Currently, there are numerous reviews summarizing the research progress on drug-loaded albumin molecules or nanoparticles. In comparison, the study of albumin-based hydrogels is a relatively small area of research, and few articles have systematically summarized the research progress of albumin-based hydrogels, especially for drug delivery and tissue engineering. Thus, this review summarizes the functional features and preparation methods of albumin-based hydrogels, different types of albumin-based hydrogels and their applications in antitumor drugs, tissue regeneration engineering, etc. Also, potential directions for future research on albumin-based hydrogels are discussed.

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