Drug nanocarrier agents based on starch-g-amino acids

Physico-chemical, structural, and adsorption properties of amino-modified starch derivatives for the removal of (in)organic pollutants from aqueous solutions

In this study, an environmentally sustainable process of crystal violet, congo red, methylene blue, brilliant green, Pb²⁺, Cd²⁺, and Zn²⁺ ions adsorption from aqueous solutions onto amino-modified starch derivatives was investigated. The degree of substitution, elemental analysis, swelling capacity, solubility, and FTIR, XRD, and SEM techniques were used to characterize the adsorbents. The influence of pH, contact time, temperature, and initial concentration has been studied to optimize the adsorption conditions. The amino-modified starch was the most effective in removing crystal violet (CV) (65.31-80.46 %) and Pb²⁺ (67.44-80.33 %) within the optimal adsorption conditions (pH 5, 10 mg dm^-3, 25 °C, 180 min). The adsorption of CV could be described by both Langmuir and Freundlich adsorption isotherms, while the adsorption of Pb²⁺ ions was better described by the Langmuir isotherm. The pseudo-second order model can be used to describe the adsorption kinetics of CV and Pb²⁺ on all tested samples. The thermodynamic study indicated that the adsorption of CV was exothermic, while the Pb²⁺ adsorption was endothermic. The simultaneous removal of CV and Pb²⁺ from the binary mixture has shown their competitive behavior. Thus, the amino-modified starch is a promising eco-friendly adsorbent for the removal of dyes and heavy metals from polluted water.

Nanocarriers for anticancer drugs: challenges and perspectives

Cancer is the second most common cause of death globally, surpassed only by cardiovascular disease. One of the hallmarks of cancer is uncontrolled cell division and resistance to cell death. Multiple approaches have been developed to tackle this disease, including surgery, radiotherapy and chemotherapy. Although chemotherapy is used primarily to control cell division and induce cell death, some cancer cells are able to resist apoptosis and develop tolerance to these drugs. The side effects of chemotherapy are often overwhelming, and patients can experience more adverse effects than benefits. Furthermore, the bioavailability and stability of drugs used for chemotherapy are crucial issues that must be addressed, and there is therefore a high demand for a reliable delivery system that ensures fast and accurate targeting of treatment. In this review, we discuss the different types of nanocarriers, their properties and recent advances in formulations, with respect to relevant advantages and disadvantages of each.

Carboxymethyl starch encapsulated 5-FU and DOX co-loaded layered double hydroxide for evaluation of its in vitro performance as a drug delivery agent

Achieving a new oral drug delivery system with controlled drug release behavior is valuable in cancer therapy. Therefore, for the first time, doxorubicin (DOX) and 5-fluorouracil (5-Fu) were simultaneously co-loaded on the as-synthesized layered double hydroxides LDH(MgAl). The resulted system was encapsulated with carboxymethyl starch to improve its efficiency for colon cancer therapy. Several characterization techniques were used to evaluate the successful synthesis of the CMS@LDH(MgAl)@DOX,5-Fu microspheres. The scanning electron microscopy result showed that the size of prepared microspheres is about 72 μm. Additionally, the presence of one broad peak at 2θ ~ 20 of the X-ray diffraction spectrum approved its amorph nature. The drug release study showed a controlled release profile with ~22% of DOX and 29% of 5-Fu. In addition, the cell viability test outcome confirmed the sustained drug release pattern from CMS@LDH(MgAl)@DOX,5-Fu against the colon cancer cell line. The results suggest that the prepared microspheres are capable to operate as an acceptable formulation for oral co-drug delivery.

Copolymers of starch, a sustainable template for biomedical applications: A review

The outstanding versatility of starch offers a source of inspiration for the development of high-performance-value-added biomaterials for the biomedical field, including drug delivery, tissue engineering and diagnostic imaging. This is because starch-based materials can be tailored to specific applications via facile grafting or other chemistries, introducing specific substituents, with starch being effectively the "template" used in all the chemical transformations discussed in this review. A considerable effort has been carried out to obtain specific tailored starch-based grafted polymers, taking advantage of its biocompatibility and biodegradability with appealing sustainability considerations. The aim of this review is to critically explore the latest research that use grafting chemistries on starch for the synthesis of products for biomedical applications. An effort is made in reviewing the literature that proposes synthetic "greener" approaches, the use of enzymes and their immobilized analogues and alternative solvent systems, including water emulsions, ionic liquids and supercritical CO₂.

Diaminated Starch: A Competitor of Chitosan with Highly Mucoadhesive Properties due to Increased Local Cationic Charge Density

The purpose of this study was to synthesize diaminated starch as a novel mucoadhesive polymer. Starch was tosylated and then reacted with ethylenediamine. The degree of amination was determined by 2,4,6-trinitrobenzene sulfonic acid assay. Properties of diaminated starch including solubility, cytotoxicity, swelling behavior, and mucoadhesion were compared to chitosan. Diaminated starch displayed 2083 ± 121.6 μmol of diamine substructures/g of polymer. At pH 6, diaminated starch exhibited a ζ potential of 6 mV, whereas it was close to zero in the case of unmodified starch. In addition, diaminated starch displayed water solubility over the entire pH range and minor cytotoxicity. The novel polymer showed pronounced swelling behavior in water increasing its initial weight 18- and 6-fold at pH 5 and 6, respectively. Moreover, diaminated starch exhibited 92-fold higher-mucoadhesivity properties than those of chitosan. According to these results, diaminated starch might be a promising novel excipient for the design of mucoadhesive formulations.