Essential oils (EOs) are complex mixtures of volatile compounds extracted from different parts of plants by different methods. There is a large diversity of these natural substances with varying properties that lead to their common use in several areas. The agrochemical, pharmaceutical, medical, food, and textile industry, as well as cosmetic and hygiene applications are some of the areas where EOs are widely included. To overcome the limitation of EOs being highly volatile and reactive, microencapsulation has become one of the preferred methods to retain and control these compounds. This review explores the techniques for extracting essential oils from aromatic plant matter. Microencapsulation strategies and the available technologies are also reviewed, along with an in-depth overview of the current research and application of microencapsulated EOs.

Environmentally friendly alternatives have become sought after upon the development of scientific research and industrial processes. Recent trends suggest biodegradable polymers as the most promising solution for synthetic microcapsule systems. Safety, efficiency, biocompatibility, and biodegradability are some of the properties that biodegradable systems in microencapsulation can provide for a broad spectrum of applications. The controlled release of encapsulated active agents is a research field that, over the years, has been constantly innovating due to the promising applications in the areas of pharmaceutical, cosmetic, textile industry, among others. This article presents an overview of different polymers with potential for microcapsule synthesis, namely, biodegradable polymers. First, natural polymers are discussed, which are divided into two categories: polysaccharide-based polymers (cellulose, starch, chitosan, and alginate) and protein polymers (gelatin). Second, synthetic polymers are described, where biodegradable polymers such as polyesters, polyamides, among others appear as examples. For each polymer, this review presents its origin, relevant properties, applications, and examples found in the literature regarding its use in biodegradable microencapsulation systems.

Fluorescence imaging is an important tool in the diverse fields of biology, chemistry and medicinal sciences.¹ Fluorescent chemoprobes such as small synthetic molecules interact specifically with the targets of interest to induce the property of fluorescence.² Benzo[a]phenoxazines function as fluorescent probes with high emission maxima, good molar extinction coefficients and photochemical stability. Moreover, these compounds are also used for labeling of amino acids, proteins and also for staining gels in gel electrophoresis experiments.³ In connection with our research findings of benzo[a]phenoxazines along with their synthesis and various applications,^4,5 the current work describes the synthesis of new benzo[a]phenoxazinium chlorides possessing the (4,6-dichloro-1,3,5-triazin-2-yl)amino at 5-position of the polycyclic system. The photophysical studies in anhydrous ethanol and water medium will be discussed along with the determination of fluorescence quantum yield.