Plant Pollen Grains: A Move Towards Green Drug and Vaccine Delivery Systems

Abstract Pollen grains and plant spores have emerged as innovative biomaterials for various applications such as drug/vaccine delivery, catalyst support, and the removal of heavy metals. The natural microcapsules comprising spore shells and pollen grain are designed for protecting the genetic materials of plants from exterior impairments. Two layers make up the shell, the outer layer (exine) that comprised largely of sporopollenin, and the inner layer (intine) that built chiefly of cellulose. These microcapsule shells, namely hollow sporopollenin exine capsules have some salient features such as homogeneity in size, non-toxic nature, resilience to both alkalis and acids, and the potential to withstand at elevated temperatures; they have displayed promising potential for the microencapsulation and the controlled drug delivery/release. The important attribute of mucoadhesion to intestinal tissues can prolong the interaction of sporopollenin with the intestinal mucosa directing to an augmented effectiveness of nutraceutical or drug delivery. Here, current trends and prospects related to the application of plant pollen grains for the delivery of vaccines and drugs and vaccine are discussed. "Image missing"

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THE QUALITY OF POLLEN GRAINS IN WHEAT MATURE ANTHERS OF ZHNITSA CULTIVAR IN PLANTA CONDITIONS

ÈKOBIOTEH ◽

10.31163/2618-964x-2021-4-1-24-32 ◽

2021 ◽

Vol 4 (1) ◽

pp. 24-32

Author(s):

A.E. Zinatullina ◽

Keyword(s):

Pollen Grains ◽

Pollen Grain ◽

Mature Pollen ◽

In Planta ◽

Spring Soft Wheat ◽

Resistant Varieties ◽

Plant Pollen ◽

Mature Anther

Biotechnological and selection investigations for making of wheat high-yielding resistant varieties require a significant amount of high-quality mature pollen. It is important to assess It is important to assess the quality of pollen grains in mature anthers in planta of the wheat genotypes included in the experiments. In the course of research the analysis of the histological status of mature anthers was carried out and qualitative cytological evaluation inside them pollen grain of spring soft wheat Zhnitsa cultivar was done in in planta conditions. It was shown that the structure of the wall locule anther presented by exothecium and endothecium is typical for cereals. It was established that 3-cell mature pollen grains are fertile (87-92%) and viable (75–80%) in general. At the same time in every mature anther abnormal pollen grains were observed and the cellular, nuclear, cytoplasmic and architectonic deviations from the norm were revealed. On the base of literature date the analysis of the reasons for the formation of abnormal pollen grains in planta was done and the classification of anomalies of plant pollen grains and the terminology used in this field of research were discussed.

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Nanomaterials as drug delivery systems with antibacterial properties: current trends and future priorities

Expert Review of Anti-infective Therapy ◽

10.1080/14787210.2021.1908125 ◽

2021 ◽

Author(s):

Khatereh Khorsandi ◽

Reza Hosseinzadeh ◽

Homa Sadat Esfahani ◽

Saeedeh Keyvani-Ghamsari ◽

Saeed Ur Rahman

Keyword(s):

Drug Delivery ◽

Drug Delivery Systems ◽

Antibacterial Properties ◽

Delivery Systems ◽

Current Trends

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Enhancement strategies for transdermal drug delivery systems: current trends and applications

Drug Delivery and Translational Research ◽

10.1007/s13346-021-00909-6 ◽

2021 ◽

Author(s):

Delly Ramadon ◽

Maeliosa T. C. McCrudden ◽

Aaron J. Courtenay ◽

Ryan F. Donnelly

Keyword(s):

Drug Delivery ◽

Stratum Corneum ◽

Transdermal Delivery ◽

Transdermal Drug Delivery ◽

Drug Delivery Systems ◽

Delivery Systems ◽

Global Market ◽

Therapeutic Drug ◽

Current Trends ◽

Transdermal Drug Delivery Systems

AbstractTransdermal drug delivery systems have become an intriguing research topic in pharmaceutical technology area and one of the most frequently developed pharmaceutical products in global market. The use of these systems can overcome associated drawbacks of other delivery routes, such as oral and parenteral. The authors will review current trends, and future applications of transdermal technologies, with specific focus on providing a comprehensive understanding of transdermal drug delivery systems and enhancement strategies. This article will initially discuss each transdermal enhancement method used in the development of first-generation transdermal products. These methods include drug/vehicle interactions, vesicles and particles, stratum corneum modification, energy-driven methods and stratum corneum bypassing techniques. Through suitable design and implementation of active stratum corneum bypassing methods, notably microneedle technology, transdermal delivery systems have been shown to deliver both low and high molecular weight drugs. Microneedle technology platforms have proven themselves to be more versatile than other transdermal systems with opportunities for intradermal delivery of drugs/biotherapeutics and therapeutic drug monitoring. These have shown that microneedles have been a prospective strategy for improving transdermal delivery systems. Graphical abstract

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Species Identification of Pinus Pollen Found in Belukha Glacier, Russian Altai Mountains, Using a Whole-Genome Amplification Method

Forests ◽

10.3390/f9080444 ◽

2018 ◽

Vol 9 (8) ◽

pp. 444

Author(s):

Fumio Nakazawa ◽

Yoshihisa Suyama ◽

Satoshi Imura ◽

Hideaki Motoyama

Keyword(s):

Species Identification ◽

Whole Genome Amplification ◽

Pollen Grains ◽

Pollen Grain ◽

Pinus Sibirica ◽

Whole Genome ◽

Accurate Identification ◽

Closely Related Species ◽

Genome Amplification ◽

Amplification Method

Pollen taxa in sediment samples can be identified based on morphology. However, closely related species do not differ substantially in pollen morphology, and accurate identification is generally limited to genera or families. Because many pollen grains in glaciers contain protoplasm, genetic information obtained from pollen grains should enable the identification of plant taxa at the species level. In the present study, species identification of Pinus pollen grains was attempted using whole-genome amplification (WGA). We used pollen grains extracted from surface snow (depth, 1.8–1.9 m) from the Belukha glacier in the summer of 2003. WGA was performed using a single pollen grain. Some regions of the chloroplast genome were amplified by PCR, and the DNA products were sequenced to identify the pollen grain. Pinus includes approximately 111 recognized species in two subgenera, four sections, and 11 subsections. The tree species Pinus sibirica and P. sylvestris are currently found at the periphery of the glacier. We identified the pollen grains from the Belukha glacier to the level of section or subsection to which P. sibirica and P. sylvestris belong. Moreover, we specifically identified two pollen grains as P. sibirica or P. cembra. Fifteen species, including P. sibirica, were candidates for the remaining pollen grain.

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Pollen characters as taxonomic evidence in some species of Dipsacaceae from Iran

Bangladesh Journal of Plant Taxonomy ◽

10.3329/bjpt.v24i2.35108 ◽

2017 ◽

Vol 24 (2) ◽

pp. 129-136 ◽

Cited By ~ 1

Author(s):

Ebadi-Nahari Mostafa ◽

Nikzat-Siahkolaee Sedigheh ◽

Eftekharian Rosa

Keyword(s):

Pollen Morphology ◽

Pollen Grains ◽

Pollen Grain ◽

Pollen Type ◽

Upgma Tree ◽

Pollen Characters ◽

Exine Ornamentation ◽

The Family ◽

The World ◽

Plant Taxon

Pollen morphology of nine species representing four genera: Cephalaria Schrad, Dipsacus L., Pterocephalus Vaill. and Scabiosa L. of the family Dipsacaceae in Iran has been investigated by means of scanning electron microscopy (SEM). The results showed that pollen grains were triporate and tricolpate. The pollen type of Scabiosa rotata Bieb. (tri- and tetraporate) is the first report in the world. The sizes of pollen grains fall into the classification group magna (pollen grain diameter 50–100 μm). Pollen shapes vary from preoblate to prolate and their polar views were triangulate and lobate. The exine ornamentation varies from gemmate in S. rotata to spinulate in the rest studied species. Species of Scabiosa have been dispersed in UPGMA tree that this confirmed the previous studies about taxonomic problems and species complexity in this genus. These results show the transfer of the some Scabisoa species to Lomelosia Raf. based on palynological characters. Pollen morphology of the family is helpful at the generic and specific level.Bangladesh J. Plant Taxon. 24(2): 129–136, 2017 (December)

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Pollen, Tapetum, and Orbicule Development inColletia paradoxaandDiscaria americana(Rhamnaceae)

The Scientific World JOURNAL ◽

10.1100/2012/948469 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 9

Author(s):

M. Gotelli ◽

B. Galati ◽

D. Medan

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Endoplasmic Reticulum ◽

Pollen Grains ◽

Pollen Grain ◽

Ultrastructural Changes ◽

Transmission Electron ◽

The Family ◽

Tapetal Cells ◽

Grain Formation

Tapetum, orbicule, and pollen grain ontogeny inColletia paradoxaandDiscaria americanawere studied with transmission electron microscopy (TEM). The ultrastructural changes observed during the different stages of development in the tapetal cells and related to orbicule and pollen grain formation are described. The proorbicules have the appearance of lipid globule, and their formation is related to the endoplasmic reticulum of rough type (ERr). This is the first report on the presence of orbicules in the family Rhamnaceae. Pollen grains are shed at the bicellular stage.

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Prunus necrotic ringspot virus Early Invasion and Its Effects on Apricot Pollen Grain Performance

Phytopathology ◽

10.1094/phyto-97-8-0892 ◽

2007 ◽

Vol 97 (8) ◽

pp. 892-899 ◽

Cited By ~ 24

Author(s):

Khalid Amari ◽

Lorenzo Burgos ◽

Vicente Pallas ◽

María Amelia Sanchez-Pina

Keyword(s):

Developmental Stages ◽

Generative Cell ◽

Pollen Grains ◽

Growth Zone ◽

Pollen Tubes ◽

Climatic Conditions ◽

Pollen Grain ◽

Ringspot Virus ◽

Prunus Necrotic Ringspot Virus

The route of infection and the pattern of distribution of Prunus necrotic ringspot virus (PNRSV) in apricot pollen were studied. PNRSV was detected both within and on the surface of infected pollen grains. The virus invaded pollen during its early developmental stages, being detected in pollen mother cells. It was distributed uniformly within the cytoplasm of uni- and bicellular pollen grains and infected the generative cell. In mature pollen grains, characterized by their triangular shape, the virus was located mainly at the apertures, suggesting that PNRSV distribution follows the same pattern as the cellular components required for pollen tube germination and cell wall tube synthesis. PNRSV also was localized inside pollen tubes, especially in the growth zone. In vitro experiments demonstrated that infection with PNRSV decreases the germination percentage of pollen grains by more than half and delays the growth of pollen tubes by ≈24 h. However, although PNRSV infection affected apricot pollen grain performance during germination, the presence of the virus did not completely prevent fertilization, because the infected apricot pollen tubes, once germinated, were able to reach the apricot embryo sacs, which, in the climatic conditions of southeastern Spain, mature later than in other climates. Thus, infected pollen still could play an important role in the vertical transmission of PNRSV in apricot.

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Pollen tube incompatibility reaction on the stigma in selfpollinated Sinapis alba L.

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.1996.017 ◽

2014 ◽

Vol 65 (1-2) ◽

pp. 101-105 ◽

Cited By ~ 1

Author(s):

Renata Śnieżko ◽

Krystyna Winiarczyk

Keyword(s):

Pollen Tube ◽

Pollen Tube Growth ◽

Pollen Grains ◽

Pollen Tubes ◽

Sinapis Alba ◽

Pollen Grain ◽

Tube Growth ◽

Sinapis Alba L ◽

Growth Changes ◽

Incompatibility Reaction

After selfpollination of <em>Sinapis alba</em> L. pollen tubes growth is inhibited on the stigma. The pollen grains germinate 3-4 hours after pollination. The pollen give rise to one or more pollen tubes. They grow along the papillae. In the place of contact between the papilla and pollen tube the pellicula is digested. Then the direction of pollen tube growth changes completely. Pollen tubes grow back on the exine of their own pollen grain, or turn into the air. The pollen tubes growth was inhibited in 6-8 hours after selfpollination. After crosspollination usually there is no incompatibility reaction.

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Characteristics and Applications of Nanostructured Nitrides Synthesized by Vapor Phase Reactions

MRS Proceedings ◽

10.1557/proc-876-r8.51 ◽

2005 ◽

Vol 876 ◽

Author(s):

Gerald Ziegenbalg ◽

Carsten Pätzold ◽

Ute Ŝingliar ◽

Rico Berthold

Keyword(s):

Silicon Nitride ◽

Amorphous Silicon ◽

Vapor Phase ◽

Elevated Temperatures ◽

Catalyst Support ◽

Chemical Properties ◽

Molar Ratio ◽

Basic Catalyst ◽

Metal Chlorides ◽

Amorphous Silicon Nitride

AbstractGas phase ammonolysis of volatile metal chlorides at elevated temperatures is a favorable way to produce nitride or oxynitride nanopowders. Their composition as well as the physico-chemical properties is determined by reaction temperature, molar ratio of the reactants and the residence time of the gases in the reaction zone. Both single and multi component powders can be obtained. Typical particle sizes are in the range of 50 to 350 nm. The specific surface can reach values up to 300 m2/g. Microporous analysis revealed the presence of pores with a diameter between 0.6 and 0.7 nm in amorphous silicon nitride. The powders can be used, depending on the characteristics, as catalyst or basic catalyst support. The paper gives an overview about vapor phase synthesis of single and multi component nitrides as well as the use of amorphous silicon nitride as a basic catalyst support for dehydrogenation of propane.

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Precise Pollen Grain Detection in Bright Field Microscopy Using Deep Learning Techniques

Sensors ◽

10.3390/s19163583 ◽

2019 ◽

Vol 19 (16) ◽

pp. 3583 ◽

Cited By ~ 3

Author(s):

Ramón Gallardo-Caballero ◽

Carlos J. García-Orellana ◽

Antonio García-Manso ◽

Horacio M. González-Velasco ◽

Rafael Tormo-Molina ◽

...

Keyword(s):

Network Architecture ◽

Detection System ◽

Pollen Grains ◽

Pollen Grain ◽

Average Value ◽

Pollen Types ◽

Pollen Concentrations ◽

Pollen Counting ◽

Estimation System ◽

3D Information

The determination of daily concentrations of atmospheric pollen is important in the medical and biological fields. Obtaining pollen concentrations is a complex and time-consuming task for specialized personnel. The automatic location of pollen grains is a handicap due to the high complexity of the images to be processed, with polymorphic and clumped pollen grains, dust, or debris. The purpose of this study is to analyze the feasibility of implementing a reliable pollen grain detection system based on a convolutional neural network architecture, which will be used later as a critical part of an automated pollen concentration estimation system. We used a training set of 251 videos to train our system. As the videos record the process of focusing the samples, this system makes use of the 3D information presented by several focal planes. Besides, a separate set of 135 videos (containing 1234 pollen grains of 11 pollen types) was used to evaluate detection performance. The results are promising in detection (98.54% of recall and 99.75% of precision) and location accuracy (0.89 IoU as the average value). These results suggest that this technique can provide a reliable basis for the development of an automated pollen counting system.

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