Natural Polymers in Micro- and Nanoencapsulation for Therapeutic and Diagnostic Applications: Part I: Lipids and Fabrication Techniques

Encapsulation, specifically microencapsulation is an old technology with increasing applications in pharmaceutical, agrochemical, environmental, food, and cosmetic spaces. In the past two decades, the advancements in the field of nanotechnology opened the door for applying the encapsulation technology at the nanoscale level. Nanoencapsulation is highly utilized in designing effective drug delivery systems (DDSs) due to the fact that delivery of the encapsulated therapeutic/diagnostic agents to various sites in the human body depends on the size of the nanoparticles. Compared to microencapsulation, nanoencapsulation has superior performance which can improve bioavailability, increase drug solubility, delay or control drug release and enhance active/passive targeting of bioactive agents to the sites of action. Encapsulation, either micro- or nanoencapsulation is employed for the conventional pharmaceuticals, biopharmaceuticals, biologics, or bioactive drugs from natural sources as well as for diagnostics such as biomarkers. The outcome of any encapsulation process depends on the technique employed and the encapsulating material. This chapter discusses in details (1) various physical, mechanical, thermal, chemical, and physicochemical encapsulation techniques, (2) types and classifications of natural polymers (polysaccharides, proteins, and lipids) as safer, biocompatible and biodegradable encapsulating materials, and (3) the recent advances in using lipids for therapeutic and diagnostic applications. Polysaccharides and proteins are covered in the second part of this chapter

Natural Polymers in Micro- and Nanoencapsulation for Therapeutic and Diagnostic Applications: Part II - Polysaccharides and Proteins

Encapsulation remains a fundamental and consistent approach of fabrication of drug and diagnostic delivery systems in the health space and natural polymers such as polysaccharides and proteins continue to play significant roles. Micro- or nanoencapsulation is employed for the conventional pharmaceuticals, biopharmaceuticals, or biologics, bioactives from natural sources and diagnostics such as biomarkers. The outcome of any encapsulation depends on the technique employed and the encapsulating material. The encapsulating materials employed influence the physical and chemical attributes of the fabricated micro- and nanocapsules. The encapsulating materials could be natural or synthetic, however, natural polymers are preferred because they are human and environmentally friendly. Polysaccharides and proteins are abundant in nature, biogenic, biocompatible, biodegradable and possess biological functions making them materials of choice for encapsulation of drugs and diagnostics. This chapter reviews the recent and advanced applications of polysaccharides and proteins as nanocarrier materials for micro- and nanoencapsulation of therapeutics and diagnostics

One-pot green synthesis of antimicrobial chitosan derivative nanocomposites to control foodborne pathogens

Food contamination by foodborne pathogens is considered a serious problem worldwide. This study aimed to show the efficacy of the one-pot green biosynthesis of nanocomposites as effective antimicrobial agents based on a water-soluble biodegradable polysaccharide and silver nitrate (AgNO3). Silver (Ag) nanoparticles were synthesized using different concentrations of AgNO3 solution (1, 2, and 3 mM) in the presence of N-quaternized chitosan and N,N,N-trimethyl chitosan chloride (TMC) as both a reducing and stabilizing agent. In addition, the structure of TMC/Ag nanocomposites was confirmed using different analytical tools including FTIR, UV-Vis, XRD, HR-TEM, FE-SEM, and EDX techniques. The FTIR spectra and UV-Vis spectra showed the main characteristic absorption peaks of Ag nanoparticles. In addition, FE-SEM images showed the formation of spherical bead-like particles on the surface of TMC. Correspondingly, the EDX spectrum showed a peak for silver, indicating the successful synthesis of Ag nanoparticles inside the TMC chains. Moreover, HR-TEM images exhibited the good distribution of Ag nanoparticles, which appeared as nano-spherical shapes. The antimicrobial activity of TMC/Ag nanocomposites was examined against three foodborne pathogens, including Salmonella Typhimurium as a Gram-negative bacterium, Bacillus subtilis as a Gram-positive bacterium and Aspergillus fumigatus as a fungus. The results showed that TMC/Ag nanocomposites had better antimicrobial activity compared with TMC alone and their antimicrobial activity increased with an increase in the concentration of Ag. The results confirmed that the TMC/Ag nanocomposites can be potentially used as an effective antimicrobial agent in food preservation.This work was supported by Cairo University-Faculty of Science fund 2020. Furthermore, AES thanks the National Research grants from MINECO, Spain, "Juan de la Cierva" [FJCI-2018-037717] and he is currently on leave from CMRDI

One-pot hydrothermal preparation of hierarchical manganese oxide nanorods for high-performance symmetric supercapacitors

An eco-friendly, new, and controllable approach for the preparation of manganese oxide (α-MnO2) nanorods has been introduced using hydrothermal reaction for supercapacitor application. The in-depth crystal structure analysis of α-MnO2 is analyzed by X-ray Rietveld refinement by using FullProf program with the help of pseudo-Voigt profile function. The developed α-MnO2 electrode attains a remarkable capacitance of 577.7 F/g recorded at a current density value of 1 A/g with an excellent cycle life when is used for 10,000 repeated cycles due to the porous nanorod-morphology assisting the ease penetration of electrolyte ions into the electroactive sites. The diffusive and capacitive contributions of the electrode have been estimated by considering standard numerical packages in Python. After successfully assembling the aqueous symmetric supercapacitor (SSC) cell by utilizing the as-prepared α-MnO2, an excellent capacitance of 163.5 F/g and energy density of 58.1 Wh/kg at the constant current density of 0.5 A/g are obtained with an expanded potential frame of 1.6 V. Moreover, the cell has exceptionally withstood up to 10,000 cycles with an ultimate capacitance retention of 94.1% including the ability to light an LED for 18 s. Such findings recommend the developed α-MnO2 electrode to be a highly felicitous electrode for the field of energy storage