Africa can be “left behind” after other advanced continents recover from the coronavirus disease 2019 (COVID-19) pandemic as reflected by the global pandemic of HIV/AIDS. In this paper, we summarize potentially adaptable, effective and innovative strategies from China, Italy, and the U.S. The purpose is to help African countries with weaker healthcare systems better respond to the COVID-19 pandemic. China, being the first to detect COVID-19 infection swiftly swung into anti-epidemic actions by the use of innovative risk communication and epidemic containment strategies. Italy and U.S., the next rapidly hit countries after China, however, experienced sustained infections and deaths due to delayed and ineffective response. Many African countries responded poorly to the COVID-19 pandemic as evidenced by the limited capacity for public health surveillance, poor leadership, low education and socioeconomic status, among others. Experience from China, Italy and U.S. suggests that a better response to the COVID-19 pandemic in Africa needs a strong public health leadership, proactive strategies, innovative risk communication about the pandemic, massive tests and isolation, and scaling-up community engagement. Lastly, African countries must collaborate with other countries to facilitate real-time information and experience exchange with other countries to avoid being left behind.

To improve liposomes’ usage as drug delivery vehicles, cryoprotectants can be utilized to prevent constituent leakage and liposome instability. Cryoprotective agents (CPAs) or cryoprotectants can protect liposomes from the mechanical stress of ice by vitrifying at a specific temperature, which forms a glassy matrix. The majority of studies on cryoprotectants demonstrate that as the concentration of the cryoprotectant is increased, the liposomal stability improves, resulting in decreased aggregation. The effectiveness of CPAs in maintaining liposome stability in the aqueous state essentially depends on a complex interaction between protectants and bilayer composition. Furthermore, different types of CPAs have distinct effective mechanisms of action; therefore, the combination of several cryoprotectants may be beneficial and novel attributed to the synergistic actions of the CPAs. In this review, we discuss the use of liposomes as drug delivery vehicles, phospholipid–CPA interactions, their thermotropic behavior during freezing, types of CPA and their mechanism for preventing leakage of drugs from liposomes.

Antifreeze proteins (AFPs) or thermal hysteresis (TH) proteins are biomolecular gifts of nature to sustain life in extremely cold environments. This family of peptides, glycopeptides and proteins produced by diverse organisms including bacteria, yeast, insects and fish act by non-colligatively depressing the freezing temperature of the water below its melting point in a process termed thermal hysteresis which is then responsible for ice crystal equilibrium and inhibition of ice recrystallisation; the major cause of cell dehydration, membrane rupture and subsequent cryodamage. Scientists on the other hand have been exploring various substances as cryoprotectants. Some of the cryoprotectants in use include trehalose, dimethyl sulfoxide (DMSO), ethylene glycol (EG), sucrose, propylene glycol (PG) and glycerol but their extensive application is limited mostly by toxicity, thus fueling the quest for better cryoprotectants. Hence, extracting or synthesizing antifreeze protein and testing their cryoprotective activity has become a popular topic among researchers. Research concerning AFPs encompasses lots of effort ranging from understanding their sources and mechanism of action, extraction and purification/synthesis to structural elucidation with the aim of achieving better outcomes in cryopreservation. This review explores the potential clinical application of AFPs in the cryopreservation of different cells, tissues and organs. Here, we discuss novel approaches, identify research gaps and propose future research directions in the application of AFPs based on recent studies with the aim of achieving successful clinical and commercial use of AFPs in the future.

The cryopreservation of red blood cells (RBCs) plays a key role in blood transfusion therapy. Traditional cryoprotectants (CPAs) are mostly organic solvents and may cause side effects to RBCs, such as hemolysis and membrane damage. Therefore, it is necessary to find CPAs with a better performance and lower toxicity. Herein, we report for the first time that N-[Tri(hydroxymethyl)methyl]glycine (tricine) showed a great potential in the cryopreservation of sheep RBCs. The addition of tricine significantly increased the thawed RBCs’ recovery from 19.5 ± 1.8% to 81.2 ± 8.5%. The properties of thawed RBCs were also maintained normally. Through mathematical modeling analysis, tricine showed a great efficiency in cryopreservation. We found that tricine had a good osmotic regulation capacity, which could mitigate the dehydration of RBCs during cryopreservation. In addition, tricine inhibited ice recrystallization, thereby decreasing the mechanical damage from ice. Tricine could also reduce oxidative damage during freezing and thawing by scavenging reactive oxygen species (ROS) and maintaining the activities of endogenous antioxidant enzymes. This work is expected to open up a new path for the study of novel CPAs and promote the development of cryopreservation of RBCs.

Stem cell therapy is a thriving topic of interest among researchers and clinicians due to evidence of its effectiveness and promising therapeutic advantage in numerous disease conditions as presented by novel biomedical research. However, extensive clinical application of stem cells is limited by its storage and transportation. The emergence of cryopreservation technology has made it possible for living organs, tissues, cells and even living organisms to survive for a long time at deep low temperatures. During the cryopreservation process, stem cell preparations are subject to three major damages: osmotic damage, mechanical damage, and peroxidative damage. Therefore, Assessing the effectiveness and safety of stem cells following cryopreservation is fundamental to the quality control of stem cell preparations. This article presents the important biosafety and quality control parameters to be assessed during the manufacturing of clinical grade stem cell products, highlights the significance of preventing cryodamage. and provides a reference for protocols in the quality control of stem cell preparations.