AQUASOMES DRUG DELIVERY PDF

Kashura It is widely used for the preparation of implants for drug delivery. The solid core provides the structural stability, while the carbohydrate coating protects against dehydration and stabilizes the ddug active molecules. This article discusses the problems faced in the delivery of clinically important peptides and presents aquasomes as a reliable approach to troubleshoot them. This property of maintaining dleivery conformational integrity of bioactive molecules has led to the proposal that aquasomes have potential as a carrier system for delivery of peptide-based pharmaceuticals.

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Nanotechnology has emerged fields of biomedical research in the last few decades the presents context is an attempt to present the brief information about nanobiotechnological applications. Aquasomes are nanoparticulate carrier system but instead of being simple nanoparticles these arse three layered self assembled structures, comprised of a solid phase nanocrystalline core coated with oligomeric film to which biochemically active molecules are adsorbed with or without modification.

Aquasomes are spherical 60— nm particles used for drug and antigen delivery. Aquasomes discovery comprises a principle from microbiology, food chemistry, biophysics and many discoveries including solid phase synthesis, supramolecular chemistry, molecular shape change and self assembly. Three types of core materials are mainly used for producing aquasomes: tin oxide, nanocrystalline carbon ceramics diamonds and brushite calcium phosphate dihydrate.

Calcium phosphate is the core of interest, owing to its natural presence in the body. The brushite is unstable and converts to hydroxyapatite upon prolong storage. Hydroxyapatite seems, therefore, a better core for the preparation of aquasomes. It is widely used for the preparation of implants for drug delivery. The solid core provides the structural stability, while the carbohydrate coating protects against dehydration and stabilizes the biochemically active molecules.

This property of maintaining the conformational integrity of bioactive molecules has led to the proposal that aquasomes have potential as a carrier system for delivery of peptide, protein, hormones, antigens and genes to specific sites. Aquasome deliver their content through specific targeting, molecular sheiling and slow sustained release process. Aquasome technology represents a patform system for conformational integrality and biochemical stability of bioactives. Their large sized and active surfaces enable them to be loaded with water insoluble drugs through non covalent processes.

Their intended route of administration is parenteral and with advancement of research in this field, other routes might be contemplated. This article reviews the principles of self assembly, the challenges of maintaining both the conformational integrity and biochemical activity of immobilized surface pairs, and the convergence of these principles into a single functional composition.

Properties like protection and preservation of fragile biological molecules, conformational integrity, and surface exposure made it as a successful carrier system for bioactive molecules like peptide, protein, hormones, antigens and genes to specific sites 1. The pharmacologically active molecule incorporated by co-polymerization, diffusion or adsorption to carbohydrate surface of pre formed nanoparticles.

These three layered structure are self assembled by non-covalent bonds. Molecules forming hydrogen bonds are hydrophilic and this confers a significant degree of organization to surrounding water molecules. In aquasomes, sugars help in molecular plasticization.

Conformational integrity of aquasomes exploited as a red blood cell substitutes, vaccines for delivery of viral antigen Epstein-Barr and Immune deficiency virus to evoke correct antibody and as targeted system for intracellular gene therapy. Aquasomes deliver their contents trough a combination of specific targeting, molecular shielding and a slow sustained release processes.

Molecules adjust their own position to reach thermodynamic minimum, true nanostructures prepared Formation of stable structure through ionic, hydrogen and van der waals links.

Use of multiple copies. For final assembly, non covalent connection between molecules must be stable. Many other carriers like prodrugs and liposomes utilized but these are prone to destructive interactions between drug and carrier in such case aquasomes proof to be worthy carrier, carbohydrate coating prevents destructive denaturing interaction between drug and solid carriers Normally, active molecules possess following qualities i.

In the aqueous state pH, temperature, solvents, salts cause denaturation 12, Hence, bio-active faces many biophysical constrain. In such case, aquasomes with natural stabilizers like various polyhydroxy sugars act as dehydroprotectant maintains water like state thereby preserves molecules in dry solid state. Role of Disaccharides: Among three layers of aquasomes, carbohydrate fulfills the objective of aquasomes. The hydroxyl groups on oligomer interact with polar and charged groups of proteins, in a same way as with water thus preserve the aqueous structure of proteins on dehydration.

These disaccharides rich in hydroxyl group help to replace the water around polar residues in protein, maintaining integrity in absence of water. The free bound mobility associated with a rich hydroxyl component creates unique hydrogen binding substrate that produces a glassy aqueous state 4, 14, Material used and its importance: Metal nano-biomaterials are used for the preparation of aquasomes.

For preparation of nanoparticles core both polymers and ceramic can be used. Polymers used are albumin, gelatin or acrylates and ceramics used are diamond particles nano-crystalline carbon ceramic , brushite, and tin oxide core 16, Ceramic materials were widely used because ceramics are structurally the most regular materials known, being crystalline high degree of order ensures.

The freshly prepared particles possess good property of adsorbing molecules within fraction of seconds. Second step followed by coating of carbohydrate epitaxially over nanocrystalline ceramic core. The commonly used coating materials 19, 20 are cellobiose, pyridoxalphosphate, sucrose and trehalose, presence of carbohydrate film prevents soft drug from changing shape and being damage when surface bound. Thirdly bio-actives molecules adsorbed which possess property of interacting with film via non-covalent and ionic interactions.

Main medical application of this aquasomes is delivery of xenobiotics and antigens Aquasomes deliver contents through combination of specific targeting, molecular shielding, and slow and sustained release process. As solid particles dispersed in aqueous environment, exhibit physical properties of colloids. Since the drug is adsorbed on to the surface of the system without further surface modification they may not find any difficulty in receptor recognition on the active site so that the pharmacological or biological activity can be achieved immediately.

In normal system, the calcium phosphate is a biodegradable ceramic. Biodegradation of ceramic in vivo is achieved essentially by monocytes and multicellular cells called osteoclasts because they intervene first at the biomaterial implantation site during inflammatory reaction. Two types of phagocytosis were reported when cells come in contact with biomaterial; either calcium phosphate crystals were taken up alone and then dissolved in the cytoplasm after disappearance of the phagosome membrane or dissolution after formation of heterophago-somes.

Phagocytosis of calcium phosphate coincided with autophagy and the accumulation of residual bodies in the cell Characterization of Aquasomes: Aquasomes are mainly characterized for structural analyses, particle size, and morphology. These are evaluated by X-ray powder diffractometery, transmission electron microscopy, and scanning electron microscopy.

The morphology and the size distribution were obtained through images of scanning electron microscopy. The chemical composition and the crystalline structure of all samples were obtained through X-ray powder diffractometery.

In this technique, the x-ray diffraction pattern of the sample is compared with the standard diffractogram, based on which the interpretations are made Formulation of Aquasomes: Principles of Self Assembly 4, 5: Self assembly implies that the constituent parts of some final product assume spontaneously prescribed structural orientations in two or three dimensional space.

The self assembly of macro molecules in the aqueous environment, either for the purpose of creating smart nano- structured materials or in the course of naturally occurring biochemistry, is governed basically by three physicochemical processes: the interactions of charged groups, dehydration effects and structural stability.

Interactions between Charged Groups: The interaction of charged group facilitates long range approach of self assembly sub units charge group also plays a role in stabilizing tertiary structures of folded proteins. The intrinsic chemical groups or adsorbed ions from the biological milieu lend to most biological and synthetic surfaces a charge polarity. Most biochemically relevant molecules, in fact are amphoteric. The interactions of charged groups such as amino-, carboxyl-, sulfate-, and phosphate-groups, facilitate the long range approach of self assembling subunits.

The long range interaction of constituent subunits beginning at an intermolecular distance of around 15 nm, is the necessary first phase of self assembly. With hydrophobic structures, long range forces may extend up to 25 nm. Charged groups also play a role in stabilizing tertiary structures of folded proteins. Hydrogen Bonding and Dehydration Effects: Hydrogen bond helps in base pair matching and stabilization secondary protein structure such as alpha helices and beta sheets.

In case of hydrophobic molecules, which are incapable of forming hydrogen bond, their tendency to repel water helps to organize the moiety to surrounding environment, organized water decreases level of entropy and is thermodynamically unfavorable, the molecule dehydrate and get self assembled. Structural Stability: Structural stability of protein in biological environment determined by interaction between charged group and Hydrogen bonds largely external to molecule and by van der waals forces largely internal to molecule experienced by hydrophobic molecules, responsible for hardness and softness of molecule and maintenance of internal secondary structures, provides sufficient softness, allows maintenance of conformation during self assembly.

Self assembly leads to altered biological activity, van der Waals need to be buffered. Van der Waals forces, most often experienced by the relatively hydrophobic molecular regions that are shielded from water, play a subtle but critical role in maintaining molecular conformation during self assembly. Van der Waals forces largely internal to the molecule also play a small but measurable role in the interaction of polypeptides with carbohydrates and related polyhydroxyloligomers.

When molecules change their shape substantially following an interaction, the energy minima assumed upon conformational denaturation tend to preclude reversal. By using the principle of self-assembly, the aquasomes are prepared in three steps i. Preparation of the core: The first step of aquasome preparation is the fabrication of the ceramic core.

The process of ceramic core preparation depends on the selection of the materials for core. These ceramic cores can be fabricated by colloidal precipitation and sonication, inverted magnetron sputtering, plasma condensation and other processes. For the core, ceramic materials were widely used because ceramics are structurally the most regular materials known. Being crystalline, the high degree of order in ceramics ensures that any surface modification will have only a limited effect on the nature of the atoms below the surface layer and thus the bulk properties of the ceramic will be preserved.

The high degree of order also ensures that the surfaces will exhibit high level of surface energy that will favor the binding of polyhydroxy oligomeric surface film. The precipitated cores are centrifuged and then washed with enough distilled water to remove sodium chloride formed during the action. The precipitates are resuspended in distilled water and passed through a fine membrane, filter to collect the particles of desired size. Two ceramic cores that are most often used are diamond and calcium phosphate.

There are number of processes to enable the carbohydrate polyhydroxy oligomers coating to adsorb epitaxially on to the surface of the nano-crystalline ceramic cores. The processes generally entail the addition of polyhydroxy oligomer to a dispersion of meticulously cleaned ceramics in ultra pure water, sonication and then lyophilization to promote the largely irreversible adsorption of carbohydrate on to the ceramic surfaces. Excess and readily desorbing carbohydrate is removed by stir cell ultra-filtration.

The commonly used coating materials are cellobiose, citrate, pyridoxalphosphate, sucrose and trehalose. Immobilization of drugs: The surface modified nano-crystalline cores provide the solid phase for the subsequent non-denaturing self assembly for broad range of biochemically active molecules. The drug can be loaded by partial adsorption electron microscopy. The drug candidates delivered through the aquasomes show better biological activity even in case of conformationally sensitive ones.

This is probably due to the presence of the unique carbohydrate coating the ceramic. Also these formulations have been found to evoke a better immunological response and could be used as immune adjuvant for proteinaceous antigens. This approach thus provides pharmaceutical scientists with new hope for the delivery of bioactive molecules. Still, considerable further study of aquasomes is necessary with respect to pharmacokinetics, toxicology, and animal studies to confirm their efficiency as well as safety, so as to establish their clinical usefulness and to launch them commercially.

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AQUASOMES DRUG DELIVERY PDF

Yozshugrel Their large sized and active surfaces enable them to be loaded with water insoluble drugs through non covalent processes. Calcium phosphate is the core of interest, owing to its natural presence in the body. Aquasomes are one of the most recently developed delivery systems that are finding a niche as peptide and protein carriers. Aquasome deliver their content through specific targeting, molecular sheiling and slow sustained release process. Three types of core materials are mainly used for producing aquasomes: The solid core provides the structural stability, while the carbohydrate coating protects against dehydration and stabilizes the biochemically active molecules. Aquasomes discovery comprises a principle from microbiology, food chemistry, biophysics and many discoveries including solid phase synthesis, supramolecular chemistry, molecular shape change and self assembly.

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Chirag Patel has published various Books, Research and Review articles. Aquasomes are nanoparticulate carrier systems but instead of being simple nanoparticles these are three layered self assembled structures, comprised of a solid phase nanocrystalline core coated with oligomeric film to which biochemically active molecules are adsorbed with or without modification. These structures are self assembled by non covalent and ionic bonds. The solid core provides the structural stability, while the carbohydrate coating protects against dehydration and stabilizes the biochemically active molecules. Properties like protection and preservation of fragile biological molecules, conformational integrity, and surface exposure made it as a successful carrier system for bioactive molecules like peptide, protein, hormones, antigens and genes to specific sites. Three types of core materials are mainly used for producing aquasomes: tin oxide, nanocrystalline carbon ceramics diamonds and brushite calcium phosphate dihydrate. Calcium phosphate is the core of interest, owing to its natural presence in the body.

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AQUASOMES: A POTENTIAL APPROACH FOR NOVEL DRUG DELIVERY

Shaktigal This article reviews the principles of self assembly, the challenges of maintaining both the conformational integrity and biochemical activity of immobilized surface pairs, and the convergence of these principles into a single functional composition. Aquasomes discovery comprises a principle from microbiology, food chemistry, biophysics and many discoveries including solid phase synthesis, supramolecular chemistry, molecular shape change and vrug assembly. This property of maintaining the conformational integrity of bioactive molecules has led to the proposal that aquasomes have potential as a carrier system for delivery of peptide-based pharmaceuticals. Article Information Nanotechnology has emerged fields of biomedical research in the last few decades the presents context is an attempt to present the brief information ddug nanobiotechnological applications. Calcium phosphate is the core of interest, owing to its natural presence in the body.

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Gall This property of maintaining the conformational integrity of bioactive molecules has led to the proposal that aquasomes have potential as a carrier system for delivery of peptide, protein, hormones, antigens and genes to specific sites. Aquasomes discovery comprises a principle from microbiology, food chemistry, biophysics and many discoveries including solid phase synthesis, supramolecular chemistry, molecular shape change and self assembly. The solid core provides the structural stability, while the carbohydrate coating protects against dehydration and stabilizes the biochemically active molecules. Aquasomes are one of the most recently developed delivery systems that are finding a niche as peptide and protein carriers. Aquasomes: a promising carrier for peptides and protein delivery.

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