scholarly journals Regulation of the Ocular Cell/Tissue Response by Implantable Biomaterials and Drug Delivery Systems

2020 ◽  
Vol 7 (3) ◽  
pp. 65 ◽  
Author(s):  
Francesco Baino ◽  
Saeid Kargozar

Therapeutic advancements in the treatment of various ocular diseases is often linked to the development of efficient drug delivery systems (DDSs), which would allow a sustained release while maintaining therapeutic drug levels in the target tissues. In this way, ocular tissue/cell response can be properly modulated and designed in order to produce a therapeutic effect. An ideal ocular DDS should encapsulate and release the appropriate drug concentration to the target tissue (therapeutic but non-toxic level) while preserving drug functionality. Furthermore, a constant release is usually preferred, keeping the initial burst to a minimum. Different materials are used, modified, and combined in order to achieve a sustained drug release in both the anterior and posterior segments of the eye. After giving a picture of the different strategies adopted for ocular drug release, this review article provides an overview of the biomaterials that are used as drug carriers in the eye, including micro- and nanospheres, liposomes, hydrogels, and multi-material implants; the advantages and limitations of these DDSs are discussed in reference to the major ocular applications.

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 975
Author(s):  
Shahrukh Zaman Akash ◽  
Farjana Yesmin Lucky ◽  
Murad Hossain ◽  
Asim Kumar Bepari ◽  
G. M. Sayedur Rahman ◽  
...  

The development of externally controlled drug delivery systems that can rapidly trigger drug release is widely expected to change the landscape of future drug carriers. In this study, a drug delivery system was developed for on-demand therapeutic effects. The thermoresponsive paraffin film can be loaded on the basis of therapeutic need, including local anesthetic (lidocaine) or topical antibiotic (neomycin), controlled remotely by a portable mini-heater. The application of mild temperature (45 °C) to the drug-loaded paraffin film allowed a rapid stimulus response within a short time (5 min). This system exploits regular drug release and the rapid generation of mild heat to trigger a burst release of 80% within 6 h of any locally administered drug. The in vitro drug release studies and in vivo therapeutic activity were observed for local anesthesia and wound healing using a neomycin-loaded film. The studies demonstrated on-demand drug release with minimized inflammation and microbial infection. This temperature-responsive drug-loaded film can be triggered remotely to provide flexible control of dose magnitude and timing. Our preclinical studies on these remotely adjustable drug delivery systems can significantly improve patient compliance and medical practice.


Author(s):  
Anamika Saxena Saxena ◽  
Santosh Kitawat ◽  
Kalpesh Gaur ◽  
Virendra Singh

The main goal of any drug delivery system is to achieve desired concentration of the drug in blood or tissue, which is therapeutically effective and nontoxic for a prolonged period. Various attempts have been made to develop gastroretentive delivery systems such as high density system, swelling, floating system. The recent developments of FDDS including the physiological and formulation variables affecting gastric retention, approaches to design single-unit and multiple-unit floating systems, and their classification and formulation aspects are covered in detail. Gastric emptying is a complex process and makes in vivo performance of the drug delivery systems uncertain. In order to avoid this variability, efforts have been made to increase the retention time of the drug-delivery systems for more than 12 hours. The floating or hydrodynamically controlled drug delivery systems are useful in such application. Background of the research: Diltiazem HCL (DTZ), has short biological half life of 3-4 h, requires rather high frequency of administration. Due to repeated administration there may be chances of patient incompliance and toxicity problems. Objective: The objective of study was to develop sustained release alginate beads of DTZ for reduction in dosing frequency, high bioavailability and better patient compliance. Methodology: Five formulations prepared by using different drug to polymer ratios, were evaluated for relevant parameters and compared. Alginate beads were prepared by ionotropic external gelation technique using CaCl2 as cross linking agent. Prepared beads were evaluated for % yield, entrapment efficiency, swelling index in 0.1N HCL, drug release study and SEM analysis. In order to improve %EE and drug release, LMP and sunflower oil were used as copolymers along with sodium alginate.


2020 ◽  
Vol 26 (33) ◽  
pp. 4174-4184
Author(s):  
Marina P. Abuçafy ◽  
Bruna L. da Silva ◽  
João A. Oshiro-Junior ◽  
Eloisa B. Manaia ◽  
Bruna G. Chiari-Andréo ◽  
...  

Nanoparticles as drug delivery systems and diagnostic agents have gained much attention in recent years, especially for cancer treatment. Nanocarriers improve the therapeutic efficiency and bioavailability of antitumor drugs, besides providing preferential accumulation at the target site. Among different types of nanocarriers for drug delivery assays, metal-organic frameworks (MOFs) have attracted increasing interest in the academic community. MOFs are an emerging class of coordination polymers constructed of metal nodes or clusters and organic linkers that show the capacity to combine a porous structure with high drug loading through distinct kinds of interactions, overcoming the limitations of traditional drug carriers explored up to date. Despite the rational design and synthesis of MOFs, structural aspects and some applications of these materials like gas adsorption have already been comprehensively described in recent years; it is time to demonstrate their potential applications in biomedicine. In this context, MOFs can be used as drug delivery systems and theranostic platforms due to their ability to release drugs and accommodate imaging agents. This review describes the intrinsic characteristics of nanocarriers used in cancer therapy and highlights the latest advances in MOFs as anticancer drug delivery systems and diagnostic agents.


2020 ◽  
Vol 26 (42) ◽  
pp. 5488-5502 ◽  
Author(s):  
Yub Raj Neupane ◽  
Asiya Mahtab ◽  
Lubna Siddiqui ◽  
Archu Singh ◽  
Namrata Gautam ◽  
...  

Autoimmune diseases are collectively addressed as chronic conditions initiated by the loss of one’s immunological tolerance, where the body treats its own cells as foreigners or self-antigens. These hay-wired antibodies or immunologically capable cells lead to a variety of disorders like rheumatoid arthritis, psoriatic arthritis, systemic lupus erythematosus, multiple sclerosis and recently included neurodegenerative diseases like Alzheimer’s, Parkinsonism and testicular cancer triggered T-cells induced autoimmune response in testes and brain. Conventional treatments for autoimmune diseases possess several downsides due to unfavourable pharmacokinetic behaviour of drug, reflected by low bioavailability, rapid clearance, offsite toxicity, restricted targeting ability and poor therapeutic outcomes. Novel nanovesicular drug delivery systems including liposomes, niosomes, proniosomes, ethosomes, transferosomes, pharmacosomes, ufasomes and biologically originated exosomes have proved to possess alluring prospects in supporting the combat against autoimmune diseases. These nanovesicles have revitalized available treatment modalities as they are biocompatible, biodegradable, less immunogenic and capable of carrying high drug payloads to deliver both hydrophilic as well as lipophilic drugs to specific sites via passive or active targeting. Due to their unique surface chemistry, they can be decorated with physiological or synthetic ligands to target specific receptors overexpressed in different autoimmune diseases and can even cross the blood-brain barrier. This review presents exhaustive yet concise information on the potential of various nanovesicular systems as drug carriers in improving the overall therapeutic efficiency of the dosage regimen for various autoimmune diseases. The role of endogenous exosomes as biomarkers in the diagnosis and prognosis of autoimmune diseases along with monitoring progress of treatment will also be highlighted.


2018 ◽  
Vol 18 (10) ◽  
pp. 857-880 ◽  
Author(s):  
Salma E. Ahmed ◽  
Nahid Awad ◽  
Vinod Paul ◽  
Hesham G. Moussa ◽  
Ghaleb A. Husseini

Conventional chemotherapeutics lack the specificity and controllability, thus may poison healthy cells while attempting to kill cancerous ones. Newly developed nano-drug delivery systems have shown promise in delivering anti-tumor agents with enhanced stability, durability and overall performance; especially when used along with targeting and triggering techniques. This work traces back the history of chemotherapy, addressing the main challenges that have encouraged the medical researchers to seek a sanctuary in nanotechnological-based drug delivery systems that are grafted with appropriate targeting techniques and drug release mechanisms. A special focus will be directed to acoustically triggered liposomes encapsulating doxorubicin.


2018 ◽  
Vol 14 (5) ◽  
pp. 432-439 ◽  
Author(s):  
Juliana M. Juarez ◽  
Jorgelina Cussa ◽  
Marcos B. Gomez Costa ◽  
Oscar A. Anunziata

Background: Controlled drug delivery systems can maintain the concentration of drugs in the exact sites of the body within the optimum range and below the toxicity threshold, improving therapeutic efficacy and reducing toxicity. Mesostructured Cellular Foam (MCF) material is a new promising host for drug delivery systems due to high biocompatibility, in vivo biodegradability and low toxicity. Methods: Ketorolac-Tromethamine/MCF composite was synthesized. The material synthesis and loading of ketorolac-tromethamine into MCF pores were successful as shown by XRD, FTIR, TGA, TEM and textural analyses. Results: We obtained promising results for controlled drug release using the novel MCF material. The application of these materials in KETO release is innovative, achieving an initial high release rate and then maintaining a constant rate at high times. This allows keeping drug concentration within the range of therapeutic efficacy, being highly applicable for the treatment of diseases that need a rapid response. The release of KETO/MCF was compared with other containers of KETO (KETO/SBA-15) and commercial tablets. Conclusion: The best model to fit experimental data was Ritger-Peppas equation. Other models used in this work could not properly explain the controlled drug release of this material. The predominant release of KETO from MCF was non-Fickian diffusion.


Author(s):  
Delly Ramadon ◽  
Maeliosa T. C. McCrudden ◽  
Aaron J. Courtenay ◽  
Ryan F. Donnelly

AbstractTransdermal drug delivery systems have become an intriguing research topic in pharmaceutical technology area and one of the most frequently developed pharmaceutical products in global market. The use of these systems can overcome associated drawbacks of other delivery routes, such as oral and parenteral. The authors will review current trends, and future applications of transdermal technologies, with specific focus on providing a comprehensive understanding of transdermal drug delivery systems and enhancement strategies. This article will initially discuss each transdermal enhancement method used in the development of first-generation transdermal products. These methods include drug/vehicle interactions, vesicles and particles, stratum corneum modification, energy-driven methods and stratum corneum bypassing techniques. Through suitable design and implementation of active stratum corneum bypassing methods, notably microneedle technology, transdermal delivery systems have been shown to deliver both low and high molecular weight drugs. Microneedle technology platforms have proven themselves to be more versatile than other transdermal systems with opportunities for intradermal delivery of drugs/biotherapeutics and therapeutic drug monitoring. These have shown that microneedles have been a prospective strategy for improving transdermal delivery systems. Graphical abstract


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3610
Author(s):  
Jialin Yu ◽  
Huayu Qiu ◽  
Shouchun Yin ◽  
Hebin Wang ◽  
Yang Li

Pluronic polymers (pluronics) are a unique class of synthetic triblock copolymers containing hydrophobic polypropylene oxide (PPO) and hydrophilic polyethylene oxide (PEO) arranged in the PEO-PPO-PEO manner. Due to their excellent biocompatibility and amphiphilic properties, pluronics are an ideal and promising biological material, which is widely used in drug delivery, disease diagnosis, and treatment, among other applications. Through self-assembly or in combination with other materials, pluronics can form nano carriers with different morphologies, representing a kind of multifunctional pharmaceutical excipients. In recent years, the utilization of pluronic-based multi-functional drug carriers in tumor treatment has become widespread, and various responsive drug carriers are designed according to the characteristics of the tumor microenvironment, resulting in major progress in tumor therapy. This review introduces the specific role of pluronic-based polymer drug delivery systems in tumor therapy, focusing on their physical and chemical properties as well as the design aspects of pluronic polymers. Finally, using newer literature reports, this review provides insights into the future potential and challenges posed by different pluronic-based polymer drug delivery systems in tumor therapy.


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