RESUMO
Honey is a mixture of 25 sugars with other bioactive substances (i.e., organic acids, enzymes, antioxidants, and vitamins) and has been known as a highly nutritious functional food. Traditionally, it has been widely used in medicinal applications to cure various diseases. The effectiveness of honey in different applications has been used for its antimicrobial activity, absorption of hydrops, cleansing, removing odor, assisting granulation, recovery of nutrition, and formation of tissue and epithelium, which proved that honey has dehydrating and preserving properties to make it ideal for the cryopreservation of cells and tissues. Cryopreservation is an advanced preservation technique for tissue, cells, organelles, or other biological specimen storage, performed by cooling the sample at a very low temperature. It is the most common approach to improved preserving fertility (sperm, embryos, and oocytes) in different species that may undergo various life-threatening illnesses and allows for the genetic screening of these cells to test the sample for diseases before use. However, with toxic cryoprotectant (CPA), cryopreservation of fertility has been challenging because of their particular structure and sensitivity to chilling. Honey's unique composition, as well as its dehydrating and preserving properties, qualify it to be used as a natural cryoprotectant. The aim of this study is to emphasize the ability of honey as a natural cryoprotectant in cryopreservation. The articles for this review were searched from Google Scholar, PubMed, Science Direct, Web of Science, and Scopus, using the keywords, honey, cryopreservation, natural cryoprotectant/CPAs, extenders, and fertility. Honey, as a natural cryoprotectant in fertility cryopreservation, yielded satisfactory results, with respect to improved post-thaw quality and viability. It is now proved as a non-toxic and highly efficient natural cryoprotectant in fertility preservation because its increasing viscosity at low temperature can provide a protective barrier to cells by reducing ice formation. Furthermore, its antioxidant property plays a vital role in protecting the cells from thermal damage by reducing the reactive oxygen species (ROS). This review provides a road map for future studies to investigate the potential of honey in the cryopreservation of other cells and tissue and contribute to the scientific research, regarding this remarkable natural product.
RESUMO
Cryopreservation is essential to store living cells and tissues for future use while maintaining the proper levels of cell functions. The use of cryoprotective agents (CPAs) to inhibit intracellular ice formation during cryopreservation is vital for cell survival, but the addition and removal of CPAs and ice recrystallization during rewarming will cause fatal injury to cells. The conventional CPA loading and unloading methods generate osmotic shocks and cause mechanical injury to biological samples, and the conventional method of rewarming using a water bath also leads to ice recrystallization and devitrification. A new CPA-loaded microparticle-based method for loading and photothermal rewarming under near-infrared (NIR) laser irradiation was proposed to overcome these difficulties. We have successfully achieved the controlled release of CPAs (2 M EG, 2 M PG, and 0.5 M trehalose) with a graphene oxide (GO, 0.04% w/v) core from a 1.5% (w/v) sodium alginate shell to the human umbilical vein endothelial cells (HUVECs) within 60 s using NIR laser irradiation (808 nm Lasever at 5000 mW/cm2) and successfully recovered the CPA-loaded cells with 0.04% (w/v) GO in 8-10 s using the same NIR irradiation. The results show that this method achieved 25% higher viability of HUVECs compared to the conventional method. In short, this study proposes a new approach for achieving controlled CPA loading to cells with a photothermal-induced strategy for cell cryopreservation.