The eye has anatomical structures that function as robust static and dynamic barriers, limiting the penetration, residence time, and bioavailability of medications administered topically. The development of polymeric nano-based drug-delivery systems (DDS) could be the solution to these challenges: it can pass through ocular barriers, offering higher bioavailability of administered drugs to targeted tissues that are otherwise inaccessible; it can stay in ocular tissues for longer periods of time, requiring fewer drug administrations; and it can be made up of polymers that are biodegradable and nano-sized, minimizing the undesirable effects of the administered molecules. Therefore, therapeutic innovations in polymeric nano-based DDS have been widely explored for ophthalmic drug-delivery applications. In this review, we will give a comprehensive overview of polymeric nano-based drug-delivery systems (DDS) used in the treatment of ocular diseases. We will then examine the current therapeutic challenges of various ocular diseases and analyze how different types of biopolymers can potentially enhance our therapeutic options. A literature review of the preclinical and clinical studies published between 2017 and 2022 was conducted. Thanks to the advances in polymer science, the ocular DDS has rapidly evolved, showing great promise to help clinicians better manage patients.

The engineering of a new type of trifunctional biopolymer-based nanosponges polymerized by cross-linking beta-cyclodextrin ethylene diamine (βCD–EDA) with bifunctional hairy nanocellulose (BHNC) is reported herein. We refer to the highly cross-linked polymerized BHNC−βCD–EDA network as BBE. βCD–EDA and BHNC were cross-linked at various ratios with the help of DMTMM (4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium) as a green activator in deionized water as a solvent, which resulted in different morphological shapes of BBE. Some of these structures were chiral due to cross-linked liquid crystalline structures. A comprehensive characterization study was done to show their unique morphological, structural, and dimensional properties of BBEs. Moreover, to further investigate and to confirm the surface modification of the precursors and final BBE structures, Fourier transform infrared and nuclear magnetic resonance spectroscopy, thermogravimetric analysis, Brunauer–Emmett–Teller analysis, and X-ray diffraction were applied. The hairy nanocellulose particles were considered as the backbone, and the immobilized cyclodextrin cavities can capture doxorubicin, which was used as a model drug molecule via host–guest inclusion complexation. Finally, the obtained BBE networks showed different and sustained drug release profiles and pH responsiveness. BBE biopolymers were tested as biocompatible nanocarriers for controlled release. We realize that these structures are too big for anti-cancer drug delivery by injection or oral intake, but these structures have a high potential to be applied in wound dressing and implants. They could also be used for capturing antibiotics, dyes, and organic compounds from wastewater.

Cellulose is the most abundant renewable biomaterial on earth and beta-cyclodextrin (BCD) is among the most commonly used biocompatible drug encapsulation agents. Combining these bio-organic materials is a very powerful approach to greatly enhance the bioavailability of many drugs. These systems also allow for optimal selective drug release profiles, high biocompatibility, as well as “green nanomedicine” approaches that are eco-friendly in their synthesis and have minimal ecological toxicity. herein, we designed a new type of green and biopolymer-based nanosponge drug carriers which is polymerized by crosslinking beta-cyclodextrin ethylene diamine (βCD-EDA) with bifunctional hairy nanocellulose (BHNC). BHNC contains, besides aldehyde groups, carboxyl groups which can react with amino groups in βCD-EDA. Firstly, the crosslinker βCD-EDA was obtained through a simple nucleophilic substitution reaction between beta-cyclodextrin carbonyl imidazole (βCD-CI) and ethylene diamine (EDA). Secondly, BHNC was functionalized with the crosslinker βCD-EDA through a facile nucleophilic substitution crosslinking reaction of the BHNC activated carboxyl groups by the amines of βCD-EDA. We refer to the polymerized highly crosslinked BHNC-βCD-EDA network as BBE. Various ratios of βCD-EDA and BHNC were polymerized with the help of DMTMM as an activator, which resulted in different morphological shapes of BBE, and thus in different release profiles and pH-responsiveness. Unlike other polymer-based βCDs and nanosponges, these new types of crosslinked polymer were prepared in a green and safe solvent (water) and with very short reaction times and at low temperatures. Finally, the BBE polymers were tested as biocompatible nanocarriers for controllable doxorubicin (DOX) delivery. These hyper crosslinked polymers show a high capacity for loading DOX with extended drug release. Furthermore, breast cancer cell cultures show lower cell viability when DOX was loaded in various BBEs than control samples or DOX alone, indicating that our DOX-BBE drug delivery systems are better anticancer agents than DOX alone.

Cellulose is the most abundant renewable biomaterial on earth and beta-cyclodextrin (BCD) is among the most commonly used biocompatible drug encapsulation agents. Combining these bio-organic materials is a very powerful approach to greatly enhance the bioavailability of many drugs. These systems also allow for optimal selective drug release profiles, high biocompatibility, as well as “green nanomedicine” approaches that are eco-friendly in their synthesis and have minimal ecological toxicity. herein, we designed a new type of green and biopolymer-based nanosponge drug carriers which is polymerized by crosslinking beta-cyclodextrin ethylene diamine (βCD-EDA) with bifunctional hairy nanocellulose (BHNC). BHNC contains, besides aldehyde groups, carboxyl groups which can react with amino groups in βCD-EDA. Firstly, the crosslinker βCD-EDA was obtained through a simple nucleophilic substitution reaction between beta-cyclodextrin carbonyl imidazole (βCD-CI) and ethylene diamine (EDA). Secondly, BHNC was functionalized with the crosslinker βCD-EDA through a facile nucleophilic substitution crosslinking reaction of the BHNC activated carboxyl groups by the amines of βCD-EDA. We refer to the polymerized highly crosslinked BHNC-βCD-EDA network as BBE. Various ratios of βCD-EDA and BHNC were polymerized with the help of DMTMM as an activator, which resulted in different morphological shapes of BBE, and thus in different release profiles and pH-responsiveness. Unlike other polymer-based βCDs and nanosponges, these new types of crosslinked polymer were prepared in a green and safe solvent (water) and with very short reaction times and at low temperatures. Finally, the BBE polymers were tested as biocompatible nanocarriers for controllable doxorubicin (DOX) delivery. These hyper crosslinked polymers show a high capacity for loading DOX with extended drug release. Furthermore, breast cancer cell cultures show lower cell viability when DOX was loaded in various BBEs than control samples or DOX alone, indicating that our DOX-BBE drug delivery systems are better anticancer agents than DOX alone.