Microfluidically Assisted Synthesis of Calcium Carbonate Submicron Particles with Improved Loading Properties

The development of advanced methods for the synthesis of nano- and microparticles in the field of biomedicine is of high interest due to a range of reasons. The current synthesis methods may have limitations in terms of efficiency, scalability, and uniformity of the particles. Here, we investigate the synthesis of submicron calcium carbonate using a microfluidic chip with a T-shaped oil supply for droplet-based synthesis to facilitate control over the formation of submicron calcium carbonate particles. The design of the chip allowed for the precise manipulation of reaction parameters, resulting in improved porosity while maintaining an efficient synthesis rate. The pore size distribution within calcium carbonate particles was estimated via small-angle X-ray scattering. This study showed that the high porosity and reduced size of the particles facilitated the higher loading of a model peptide: 16 vs. 9 mass.% for the particles synthesized in a microfluidic device and in bulk, correspondingly. The biosafety of the developed particles in the concentration range of 0.08-0.8 mg per plate was established by the results of the cytotoxicity study using mouse fibroblasts. This innovative approach of microfluidically assisted synthesis provides a promising avenue for future research in the field of particle synthesis and drug delivery systems.

Chitosan Derivatives as Carriers for Drug Delivery and Biomedical Applications

Over the past few decades, chitosan (CS) has gained the attention of researchers investigating newer biomaterial-based carriers for drugs in pharmaceutical and biomedical research. Combined with its nontoxic behavior, biodegradability, and biocompatibility, chitosan has found widespread applications in the fields of drug delivery, tissue engineering, and cosmetics. As a novel drug carrier, chitosan is regarded as one of the promising biomaterials in the pharmaceutical industry. The extensive use of this cationic biopolysaccharide in the delivery of therapeutic agents has brought a few limitations of chitosan into the limelight. Various chemical modifications of chitosan can minimize these limitations and improve the efficacy of chitosan as a drug carrier. The effectiveness of several chemically modified chitosan derivatives, including trimethyl chitosan, thiolated chitosan, PEGylated chitosan, and other chitosan derivatives, has been investigated by many researchers for the controlled and target specific delivery of therapeutics. The chemically modified chitosan derivatives exhibited greater importance in the current scenario on drug delivery due to their solubility in wide range of media along with their interaction with pharmaceutically active ingredients. Chitosan derivatives have also attracted attention in several biomedical fields, including wound healing, hyperthermia therapy, tissue engineering, and bioadhesives. The present review narrates the sources and common physicochemical properties of chitosan, including several important synthetic modifications to obtain chemically modified chitosans and their applications in target-specific drug delivery, along with several biomedical applications.

Silk Fibroin as an Efficient Biomaterial for Drug Delivery, Gene Therapy, and Wound Healing

Silk fibroin (SF), an organic material obtained from the cocoons of a silkworm Bombyx mori, is used in several applications and has a proven track record in biomedicine owing to its superior compatibility with the human body, superb mechanical characteristics, and its controllable propensity to decay. Due to its robust biocompatibility, less immunogenic, non-toxic, non-carcinogenic, and biodegradable properties, it has been widely used in biological and biomedical fields, including wound healing. The key strategies for building diverse SF-based drug delivery systems are discussed in this review, as well as the most recent ways for developing functionalized SF for controlled or redirected medicines, gene therapy, and wound healing. Understanding the features of SF and the various ways to manipulate its physicochemical and mechanical properties enables the development of more effective drug delivery devices. Drugs are encapsulated in SF-based drug delivery systems to extend their shelf life and control their release, allowing them to travel further across the bloodstream and thus extend their range of operation. Furthermore, due to their tunable properties, SF-based drug delivery systems open up new possibilities for drug delivery, gene therapy, and wound healing.

Folate encapsulation in PEG-diamine grafted mesoporous Fe3O4 nanoparticles for hyperthermia and in vitro assessment

Effective and targeted delivery of the antitumour drugs towards the specific cancer spot is the major motive of drug delivery. In this direction, suitably functionalised magnetic iron oxide nanoparticles (NPs) have been utilised as a theranostic agent for imaging, hyperthermia and drug delivery applications. Herein, the authors reported the preparation of multifunctional polyethyleneglycol-diamine functionalised mesoporous superparamagnetic iron oxide NPs (SPION) prepared by a facile solvothermal method for biomedical applications. To endow targeting ability towards tumour site, folic acid (FA) is attached to the amine groups which are present on the NPs surface by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide chemistry. FA attached SPION shows good colloidal stability and possesses high drug-loading efficiency of ∼ 96% owing to its mesoporous nature and the electrostatic attachment of daunosamine (NH3+) group of doxorubicin (DOX) towards the negative surface charge of carboxyl and hydroxyl group. The NPs possess superior magnetic properties in result endowed with high hyperthermic ability under alternating magnetic field reaching the hyperthermic temperature of 43°C within 223 s at NP's concentration of 1 mg/ml. The functionalised NPs possess non-appreciable toxicity in breast cancer cells (MCF-7) which is triggered under DOX-loaded SPION.

pH Sensitive Hydrogels in Drug Delivery: Brief History, Properties, Swelling, and Release Mechanism, Material Selection and Applications

Improving the safety efficacy ratio of existing drugs is a current challenge to be addressed rather than the development of novel drugs which involve much expense and time. The efficacy of drugs is affected by a number of factors such as their low aqueous solubility, unequal absorption along the gastrointestinal (GI) tract, risk of degradation in the acidic milieu of the stomach, low permeation of the drugs in the upper GI tract, systematic side effects, etc. This review aims to enlighten readers on the role of pH sensitive hydrogels in drug delivery, their mechanism of action, swelling, and drug release as a function of pH change along the GI tract. The basis for the selection of materials, their structural features, physical and chemical properties, the presence of ionic pendant groups, and the influence of their pKa and pKb values on the ionization, consequent swelling, and targeted drug release are also highlighted.