Three-dimensional hydroxyapatite-chitosan (HA-CS) composites were formulated via solid-liquid technic and freeze-drying. The prepared composites had an apatitic nature, which was demonstrated by X-ray diffraction and Infrared spectroscopy analyses. The impact of the solid/liquid (S/L) ratio and the content and the molecular weight of the polymer on the composite mechanical strength was investigated. An increase in the S/L ratio from 0.5 to 1 resulted in an increase in the compressive strength for HA-CSL (CS low molecular weight: CSL) from 0.08 ± 0.02 to 1.95 ± 0.39 MPa and from 0.3 ± 0.06 to 2.40 ± 0.51 MPa for the HA-CSM (CS medium molecular weight: CSM). Moreover, the increase in the amount (1 to 5 wt%) and the molecular weight of the polymer increased the mechanical strength of the composite. The highest compressive strength value (up to 2.40 ± 0.51 MPa) was obtained for HA-CSM (5 wt% of CS) formulated at an S/L of 1. The dissolution tests of the HA-CS composites confirmed their cohesion and mechanical stability in an aqueous solution. Both polymer and apatite are assumed to work together, giving the synergism needed to make effective cylindrical composites, and could serve as a promising candidate for bone repair in the orthopedic field.

To meet the needs of a rapidly expanding global population, farmers will need more fertilizers than ever before to maintain a steady supply of affordable, nutritious food. The formulation of controlled release fertilizers (CRF) to synchronize nutrient release according to the demand of plants has emerged as a viable solution to the current problems associated with the poor nutrient usage efficiency of fertilizers. Yet, the greatest obstacle that still stands in the way of broad use of CRF in agriculture is their expensive manufacturing costs. The first section of this analysis focuses on broad topics related to CRF. Afterward, the differences between several cost‐effective raw materials and some of the production techniques used to make CRF are examined. Furthermore, the emerging field of “smart” coating materials, such as stimuli‐responsive coatings, which can accurately tailor nutrients delivery to the demands of the vegetation, is discussed, and the most important research work that could lead to their extensive use in agriculture is pointed out. The purpose of this review is to provide a strong assessment of CRF's development over the past several years by highlighting innovations and providing in‐depth analysis of prevailing patterns to better understand the future of agriculture.

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A composite based on hydroxyapatite (HA) and chitosan (CS) combined with ciprofloxacin (CIP) was formulated by the solid–liquid mixing method. The optimization of the solid to the liquid ratio and the use of chitosan in a small amount (≤5 wt%) promoted the preparation of stable and rigid monoliths. A synergistic effect of CS and CIP contents on the compressive strength of the CIP‐loaded composite was evidenced. The compressive strength of the fabricated biocomposite ranged in values from 1 to 6 MPa, comparable to those reported for cancellous bone. The improvement of the mechanical properties with the increase of the rate of organic components was correlated with the diminution of the surface area and the reduction in the pore volume of the specimens. On the other hand, the in vitro release experiments of the antibiotic indicated a sustained and controlled release of CIP over 10 days. Moreover, in vitro antibacterial tests performed on the biocomposite HA‐CS5‐CIP showed significant inhibition of Staphylococcus aureus and Escherichia coli pathogens. According to the showed results, the formulated composite with three‐phase components could be a promising material for bone repair and local antibiotic release for the treatment of bone infections.

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