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A drug delivery system (DDS) is a useful technology that efficiently delivers a target drug to a patient's specific diseased tissue with minimal side effects. DDS is a convergence of several areas of study, comprising pharmacy, medicine, biotechnology, and chemistry fields. In the traditional pharmacological concept, developing drugs for disease treatment has been the primary research field of pharmacology. The significance of DDS in delivering drugs with optimal formulation to target areas to increase bioavailability and minimize side effects has been recently highlighted. In addition, since the burst release found in various DDS platforms can reduce drug delivery efficiency due to unpredictable drug loss, many recent DDS studies have focused on developing carriers with a sustained release. Among various drug carriers, mesoporous silica DDS (MS-DDS) is applied to various drug administration routes, based on its sustained releases, nanosized porous structures, and excellent solubility for poorly soluble drugs. However, the synthesized MS-DDS has caused complications such as toxicity in the body, long-term accumulation, and poor excretion ability owing to acid treatment-centered manufacturing methods. Therefore, biosilica obtained from diatoms, as a natural MS-DDS, has recently emerged as an alternative to synthesized MS-DDS. This natural silica carrier is an optimal DDS platform because culturing diatoms is easy, and the silica can be separated from diatoms using a simple treatment. In this review, we discuss the manufacturing methods and applications to various disease models based on the advantages of biosilica. [ABSTRACT FROM AUTHOR]

The Gonggeom-ji reservoir is an agricultural one built for rice farming during the Proto-Three Kingdoms period and was designated as Gyeongsangbuk-do monument No. 121 because of its high historical value. The Nakdonggang National Institute of Biological Resources has been conducting paleontological and paleoenvironmental studies on major wetlands from Korea since 2016, as well as diatom, geological, and depth distribution analyses on the sedimentary soil of Gonggeom-ji. This study summarized the description and ecological characteristics of six newly recorded diatoms (Gomphonema lacusrankala, Pinnularia diandae, P. gibba var. hyaline, P. lacunarum, Sellaphora labda var. nipponica, Stauroneis angustilancea) found in samples collected through drilling in Gonggeom-ji in 2019. [ABSTRACT FROM AUTHOR]

Late Holocene diatoms were identified from four sediment cores from the Gonggeomji Wetland in Korea. In total, 52 diatom species belonging to three classes, 21 families, and 29 genera were investigated. Of these, 14 species were new records for Korea: Caloneis wardii, Cocconeis klamathensis, Encyonema vulgare, Eunotia myrmica, Fallacia californica, Gomphonema asiaticum, Gomphonema insigniturris, Gomphonema neoapiculatum, Gomphonema tumens, Pinnularia fusana, Pinnularia parvulissima, Punctastriata lancettula, Sellaphora capitata, and Staurosira dimorpha. Eleven taxa could not be identified to the species level. All identified diatoms are illustrated by high-quality scanning electron microphotographs, reference taxonomic data, dimensions of the observed cells, and information on ecology and distribution are included. [ABSTRACT FROM AUTHOR]

Thalassiosira species are an important component of phytoplankton populations, and most species are considered cosmopolitan. Many authors have investigated the diversity of Thalassiosira species in order to understand their ecological roles in local areas. Our regional taxonomic study revealed the presence of 44 Thalassiosira species at 124 sites in Korean coastal waters. Of these, 14 species are newly reported in Korean waters and are described in detail with external and internal valve illustrations. Some morphologically confused taxa, such as the Thalassiosira s.s. group, T. curviseriata/ T. tealata, T. simonsenii/ Planktoniella blanda and T. proschkinae/ T. spinulata, are clearly distinguished using additional morphological criteria. In addition, the full biogeographical distribution of Thalassiosira is described and compared with the Korean species. Korean waters seem to be the 'Maginot Line' for the cold- and warm-water Thalassiosira species. Knowledge of Thalassiosira species diversity will increase with more intensive work in relatively little-studied regions, such as the Indo-Pacific and tropical Atlantic Oceans. [ABSTRACT FROM AUTHOR]

Lagoons are natural bodies of water that are isolated from the sea due to the development of a sand bar or spit. Each lagoon has distinct ecological characteristics, and these sites also serve as popular tourist attractions because they are common habitats for migratory birds and are characterized by beautiful natural scenery. Lagoons also have distinct ecological characteristics from those of their associated estuaries, and there are active research efforts to classify, qualify, and quantify the high biodiversity of lagoons. The lagoons in Korea are primarily distributed in the East Sea, and are represented by Hwajinpo, Yeongrangho, and Gyeongpoho. Here, we report the discovery of 11 unrecorded diatom species (Diploneis didyma, Mastogloia elliptica, Cosmioneis citriformis, Haslea crucigera, Pinnularia bertrandii, Pinnularia nodosa var. percapitata, Gyrosigma sinense, Gomphonema guaraniarum, Gomphonema italicum, Navicula freesei, Trybionella littoralis var. tergestina) among samples collected from the Hwajinpo, Hyangho, Maeho, Gapyeongri wetland, Cheonjinho, and Gyeongpoho lagoons in Korea during a survey from 2018–2020. We present the taxonomic characteristics, ecological information, habitat environmental conditions, and references for these 11 species. [ABSTRACT FROM AUTHOR]

Suncheonman Bay, Korea's most representative estuary, is an invasive coastal wetland composed of 22.6 km2 of tidal flats surrounded by the Yeosu and Goheung Peninsulas. In January 2006, this region was registered in the Ramsar Convention list in Korea, representing the first registered wetland. Estuaries are generally known to have high species diversity. In particular, several studies have been conducted on planktonic and epipelic diatoms as primary producers. Suncheonman Bay has already been involved in many biological and geochemical studies, but fossil diatoms have not been evaluated. Therefore, we investigated fossil diatoms in Suncheonman Bay and introduced sub-fossil diatoms recorded in Korea. One sedimentary core has been extracted in 2018. We identified 87 diatom taxa from 52 genera in the SCW03 core sample. Of these, six species represent new records in Korea: Cymatonitzschia marina, Fallacia hodgeana, Navicula mannii, Metascolioneis tumida, Surirella recedens, and Thalassionema synedriforme. These six newly recorded diatom species were examined by light microscopy and scanning electron microscopy. The ecological habitats for all the investigated taxa are presented. [ABSTRACT FROM AUTHOR]