Core-shell micro/nanocapsules: from encapsulation to applications.

Encapsulation is the way to wrap or coat one substance as a core inside another tiny substance known as a shell at micro and nano scale for protecting the active ingredients from the exterior environment. A lot of active substances, such as flavours, enzymes, drugs, pesticides, vitamins, in addition to catalysts being effectively encapsulated within capsules consisting of different natural as well as synthetic polymers comprising poly(methacrylate), poly(ethylene glycol), cellulose, poly(lactide), poly(styrene), gelatine, poly(lactide-co-glycolide)s, and acacia. The developed capsules release the enclosed substance conveniently and in time through numerous mechanisms, reliant on the ultimate use of final products. Such technology is important for several fields counting food, pharmaceutical, cosmetics, agriculture, and textile industries. The present review focuses on the most important and high-efficiency methods for manufacturing micro/nanocapsules and their several applications in our life.

Impact of Poly (Styrene-Acrylic Acid) Latex Nanoparticles on Colorectal and Cervical Cancer Cells.

Polymer nanoparticles are a promising approach for cancer treatment and detection, due to their biocompatibility, biodegradability, targeting capabilities, capacity for drug loading and long blood circulation time. This study aims to evaluate the impact of poly (styrene-acrylic acid) latex particles on colorectal and cervical cancer cells for anti-tumor efficiency. Latex particles were synthesized by a surfactant-free radical emulsion polymerization process and the obtained polymer particles were characterized in terms of size, size distribution, morphology using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and electrokinetic property (i.e., zeta potential). Human colorectal and cervical cancer, and normal cell lines, were then treated with different concentrations of poly (styrene-acrylic acid) latex particles. The cell morphology changes were pointed out using an optical microscope and the nanoparticles' (NPs) cell cytotoxicity was evaluated using MTT assay. The obtained results showed that poly (styrene-acrylic acid) latex particles are effective against colorectal and cervical cancer cells if treated with an appropriate particle concentration for 48 h. In addition, it showed that normal cells are the least affected by this treatment. This indicates that these NPs are safe as a drug delivery carrier when used at a low concentration.

Polysaccharide Chemistry in Drug Delivery, Endocrinology, and Vaccines.

Polysaccharides, due to their outstanding properties, have attracted the attention of researchers, working in the biomedical field and especially of those working in drug delivery. Modified/functionalized polysaccharides further increase the importance for various applications. Delivery of therapeutics for diverse ailments in different endocrine glands and hormones safely, is a focal point of researchers working in the field. Among the routes followed, the transdermal route is preferred due to non-exposure of active moieties to the harsh gastric environment and first-pass metabolism. This review starts with the overview of polysaccharides used for the delivery of various therapeutic agents. Advantages of polysaccharides used in the transdermal route are addressed in detail. Types of polysaccharides will be elaborated through examples, and in this context, special emphasis will be on the polysaccharides being used for synthesis of the membranes/films. Techniques employed for their modification to design novel carriers for therapeutics delivery will also be discussed. The review will end with a brief discussion on recent developments and future perspectives for delivery of therapeutic agents, and vaccine development.

Exploiting proteases for cancer theranostic through molecular imaging and drug delivery.

The measurement of biological processes at a molecular and cellular level serves as a basis for molecular imaging. As compared with traditional imaging approaches, molecular imaging functions to probe molecular anomalies that are the basis of a disease rather than the evaluation of end results of these molecular changes. Proteases play central role in tumor invasion, angiogenesis and metastasis thus can be exploited as a target for imaging probes in early diagnosis and treatment of tumors. Molecular imaging of protease has undergone tremendous breakthroughs in the field of diagnosis. It allows the clinicians not only to see the tumor location but also provides an insight into the expression and activity of different types of markers associated with the tumor microenvironment. These imaging techniques are expected to have a huge impact on early cancer detection and personalized cancer treatment. Effective development of protease imaging probes with the highest in vivo biocompatibility, stability and most appropriate pharmacokinetics for clinical translation will upsurge the success level of early cancer detection and treatment.

Human serum albumin nanoparticles as nanovector carriers for proteins: Application to the antibacterial proteins "neutrophil elastase" and "secretory leukocyte protease inhibitor".

The use of proteins and defined amino acid sequences as therapeutic drugs have gained a certain interest in the past decade. However, protein encapsulation within protein nanoparticles was never endeavored. For this reason, human serum albumin (HSA) nanoparticles were prepared by nanoprecipitation method. The process was optimized, and particles were obtained with a size of 120 nm and zeta potential of -25 mV. Neutrophil elastase (NE) and secretory leukocyte protease inhibitor (SLPI) were encapsulated separately within HSA nanoparticles. Gel electrophoresis and western blot studies demonstrate the successful encapsulation and the stability of the particles. On the other hand, enzymatic assays show that encapsulated NE lost its proteolytic activity, whereas encapsulated SLPI maintained its inhibitory property. In addition, the antibacterial studies showed that both formulations were able to drastically reduce bacterial growth of Pseudomonas aeruginosa. This work showed the possibility of using both NE and SLPI as anti-bacterial agents through encapsulation within HSA nanoparticles.

Protein-Based Nanoparticle Preparation via Nanoprecipitation Method.

Nanoparticles are nowadays largely investigated in the field of drug delivery. Among nanoparticles, protein-based particles are of paramount importance since they are natural, biodegradable, biocompatible, and nontoxic. There are several methods to prepare proteins containing nanoparticles, but only a few studies have been dedicated to the preparation of protein- based nanoparticles. Then, the aim of this work was to report on the preparation of bovine serum albumin (BSA)-based nanoparticles using a well-defined nanoprecipitation process. Special attention has been dedicated to a systematic study in order to understand separately the effect of each operating parameter of the method (such as protein concentration, solvent/non-solvent volume ratio, non-solvent injection rate, ionic strength of the buffer solution, pH, and cross-linking) on the colloidal properties of the obtained nanoparticles. In addition, the mixing processes (batch or drop-wise) were also investigated. Using a well-defined formulation, submicron protein-based nanoparticles have been obtained. All prepared particles have been characterized in terms of size, size distribution, morphology, and electrokinetic properties. In addition, the stability of nanoparticles was investigated using Ultraviolet (UV) scan and electrophoresis, and the optimal conditions for preparing BSA nanoparticles by the nanoprecipitation method were concluded.

Nanoprecipitation process: From encapsulation to drug delivery.

Drugs encapsulation is a suitable strategy in order to cope with the limitations of conventional dosage forms such as unsuitable bioavailability, stability, taste, and odor. Nanoprecipitation technique has been used in the pharmaceutical and agricultural research as clean alternative for other drug carrier formulations. This technique is based on precipitation mechanism. Polymer precipitation occurs after the addition of a non-solvent to a polymer solution in four steps mechanism: supersaturation, nucleation, growth by condensation, and growth by coagulation that leads to the formation of polymer nanoparticles or aggregates. The scale-up of laboratory-based nanoprecipitation method shows a good reproducibility. In addition, flash nanoprecipitation is a good strategy for industrial scale production of nanoparticles. Nanoprecipitation is usually used for encapsulation of hydrophobic or hydrophilic compounds. Nanoprecipitation was also shown to be a good alternative for the encapsulation of natural compounds. As a whole, process and formulation related parameters in nanoprecipitation technique have critical effect on nanoparticles characteristics. Biodegradable or non-biodegradable polymers have been used for the preparation of nanoparticles intended to in vivo studies. Literature studies have demonstrated the biodistribution of the active loaded nanoparticles in different organs after administration via various routes. In general, in vitro drug release from nanoparticles prepared by nanoprecipitation includes two phases: a first phase of "burst release" which is followed by a second phase of prolonged release. Moreover, many encapsulated active molecules have been commercialized in the pharmaceutical market.

Protein-based nanoparticles: From preparation to encapsulation of active molecules.

Nowadays, nanotechnology has become very integrated in the domain of pharmaceutical sciences since nanoparticle dispersions show various advantages as drug carriers. Among nanoparticles, the protein-based ones are of paramount importance. In fact, protein nanoparticles show many advantages over other types of nanoparticles, they are often non-toxic and biodegradable. In this review, the most common preparation methods of protein nanoparticles were targeted. In addition, the factors affecting their dispersions and the concepts of drug loading and drug release are also highlighted. It was obvious that each method can be optimized for a given protein. This issue was discussed in depth in the light of the current state of art, and supported by evidences for each method from the literature. In addition, it was concluded that the processing parameters strongly affect the properties of nanoparticles dispersion.