scholarly journals Overview of implantable and injectable biomaterials in immunotherapy

2021 ◽  
Vol 16 (1) ◽  
pp. 195-201
Author(s):  
Prerana Prakash ◽  
Pushpa Agrawal ◽  
AH Manjunatha Reddy
Keyword(s):  
Drug Delivery ◽  
Immune Response ◽  
Side Effects ◽  
Drug Release ◽  
Cancer Vaccines ◽  
Release Kinetics ◽  
Local Drug Delivery ◽  
Systemic Immune Response ◽  
Immunomodulatory Agents ◽  
Target Side

Immunotherapy has shown promising applications in cancer treatment as it boosts the systemic immune response. Existing immunotherapy strategies have certain drawbacks which can be addressed by engineered biomaterials. In this review, we focused on advanced immunotherapy methods involving implantable and injectable biomaterials for the treatment of cancer. Engineered biomaterials as carriers for immunomodulatory agents aid in the local drug delivery, thus reducing the frequency of off-target side effects. Also, biomaterial-based cancer vaccines have the potential to target specific tissues by finely altering the physical properties of the drug to achieve desired drug release kinetics.

scholarly journals Accelerating thrombolysis using a precision and clot-penetrating drug delivery strategy by nanoparticle-shelled microbubbles

2020 ◽  
Vol 6 (31) ◽  
pp. eaaz8204
Author(s):  
Siyu Wang ◽  
Xixi Guo ◽  
Weijun Xiu ◽  
Yang Liu ◽  
Lili Ren ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Side Effects ◽  
Drug Release ◽  
Controlled Delivery ◽  
Drug Penetration ◽  
Ultrasound Stimulation ◽  
Tissue Plasminogen ◽  
Residual Thrombus ◽  
Time Critical ◽  
Target Side

Conventional thrombolytic drugs for vascular blockage such as tissue plasminogen activator (tPA) are challenged by the low bioavailability, off-target side effects and limited penetration in thrombi, leading to delayed recanalization. We hypothesize that these challenges can be addressed with the targeted and controlled delivery of thrombolytic drugs or precision drug delivery. A porous and magnetic microbubble platform is developed to formulate tPA. This system can maintain the tPA activity during circulation, be magnetically guided to the thrombi, and then remotely activated for drug release. The ultrasound stimulation also improves the drug penetration into thrombi. In a mouse model of venous thrombosis, the residual thrombus decreased by 67.5% when compared to conventional injection of tPA. The penetration of tPA by ultrasound was up to several hundred micrometers in thrombi. This strategy not only improves the therapeutic efficacy but also accelerates the lytic rate, enabling it to be promising in time-critical thrombolytic therapy.

scholarly journals Development of a biodegradable antifibrotic local drug delivery system for glaucoma microstents

2018 ◽  
Vol 38 (4) ◽  
Author(s):  
Thomas Stahnke ◽  
Stefan Siewert ◽  
Thomas Reske ◽  
Wolfram Schmidt ◽  
Klaus-Peter Schmitz ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Release Kinetics ◽  
Caffeic Acid Phenethyl Ester ◽  
Local Drug Delivery ◽  
Fat Depots ◽  
Fat Depot ◽  
Local Drug Delivery System

To prevent implant failure due to fibrosis is a major objective in glaucoma research. The present study investigated the antifibrotic effects of paclitaxel (PTX), caffeic acid phenethyl ester (CAPE), and pirfenidone (PFD) coated microstent test specimens in a rat model. Test specimens based on a biodegradable blend of poly(4-hydroxybutyrate) biopolymer and atactic poly(3-hydroxybutyrate) (at.P(3HB)) were manufactured, equipped with local drug delivery (LDD) coatings, and implanted in the subcutaneous white fat depot. Postoperatively, test specimens were explanted and analyzed for residual drug content. Fat depots including the test specimens were histologically analyzed. In vitro drug release studies revealed an initial burst for LDD devices. In vivo, slow drug release of PTX was found, whereas it already completed 1 week postoperatively for CAPE and PFD LDD devices. Histological examinations revealed a massive cell infiltration in the periphery of the test specimens. Compact fibrotic capsules around the LDD devices were detectable at 4–36 weeks and least pronounced around PFD-coated specimens. Capsules stained positive for extracellular matrix (ECM) components. The presented model offers possibilities to investigate release kinetics and the antifibrotic potential of drugs in vivo as well as the identification of more effective agents for a novel generation of drug-eluting glaucoma microstents.

Design, Synthesis and Studies on Novel Polymeric Prodrugs of Erlotinib for Colon Drug Delivery

2020 ◽  
Vol 20 ◽  
Author(s):  
Sahil Kumar ◽  
Bandna Sharma ◽  
Tilak R. Bhardwaj ◽  
Rajesh K. Singh
Keyword(s):  
Drug Delivery ◽  
Colon Cancer ◽  
Drug Release ◽  
Anticancer Agents ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Specific Treatment ◽  
Drug Conjugates ◽  
Polymer Drug Conjugates

Aims: In the present study, polymer-drug conjugates were synthesized based on azo-bond cleavage drug delivery approach for targeting erlotinib as anticancer drug specifically to the colon for the proficient treatment of colon cancer. Background: Colon cancer (CC) is the third commonly detected tumor worldwide and it make up about 10 % of all cases of cancers. Most of the chemotherapeutic drugs available for treating colon cancer are not only toxic to cancerous cells but also to the normal healthy cells. Among the various approaches to get rid of the adverse effects of anticancer agents, prodrugs are one of the most imperative approaches. Objective: The objective of the study is to chemically modify the erlotinib drug through azo-bond linkage and suitable spacer which will be finally linked to polymeric backbone to give desired polymer linked prodrug. The azo reductase enzyme present in colon is supposed to cleave the azo-bond specifically and augment the drug release at the colon. Methods: The synthesized conjugates were characterized by IR and 1H-NMR spectroscopy. The cleavage of aromatic azobond resulted in a potential colon-specific liberation of drug from conjugate studied in rat fecal contents. In vitro release profiles of polyphosphazene-linked conjugates of erlotinib have been studied at pH 1.2, pH 6.8 and pH 7.4. The stability study was designed to exhibit that free drug was released proficiently and unmodified from polyphosphazene-erlotinib conjugates having aromatic azo-bond in artificial colon conditions. Results: The synthesized conjugates were demonstrated to be stable in simulated upper gastro-intestinal tract conditions. The drug release kinetics shows that all the polymer-drug conjugates of erlotinib follow zero-order release kinetics which indicates that the drug release from the polymeric backbone is independent of its concentration. Kinetic study of conjugates with slope (n) shows the anomalous type of release with an exponent (n) > 0.89 indicating a super case II type of release. Conclusion: These studies indicate that polyphosphazene linked drug conjugates of erlotinib could be the promising candidates for the site-specific treatment of colon cancer with least detrimental side-effects.

Nanoporous anodic titanium dioxide layers as potential drug delivery systems: Drug release kinetics and mechanism

2016 ◽  
Vol 143 ◽  
pp. 447-454 ◽  
Author(s):  
Magdalena Jarosz ◽  
Anna Pawlik ◽  
Michał Szuwarzyński ◽  
Marian Jaskuła ◽  
Grzegorz D. Sulka
Keyword(s):  
Drug Delivery ◽  
Titanium Dioxide ◽  
Drug Release ◽  
Drug Delivery Systems ◽  
Release Kinetics ◽  
Delivery Systems ◽  
Kinetics And Mechanism ◽  
Potential Drug ◽  
Drug Release Kinetics

scholarly journals COMPARATIVE EVALUATION OF SELECTED POLYMERS AND PLASTICIZER ON TRANSDERMAL DRUG DELIVERY SYSTEM

2018 ◽  
Vol 10 (1) ◽  
pp. 67
Author(s):  
Bhawana Sethi ◽  
Rupa Mazumder
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Propylene Glycol ◽  
Drug Delivery System ◽  
Transdermal Drug Delivery ◽  
Release Kinetics ◽  
Content Uniformity ◽  
Transdermal Drug Delivery System ◽  
Transdermal Patches

Objective: The present work was aimed at preparation of transdermal patches by a solvent casting method using a varying concentration of polymers i.e. methocel (K15 and K100), ethocel (4 and 10), gelatin, chitosan, eudragit (RL and RS) grade using plasticizer (glycerin and propylene glycol).Methods: The ratio of drug to polymers and plasticizer was varied and the effect of formulation variables was studied. Prepared transdermal patches were evaluated for physicochemical properties, in-vitro permeation studies, content uniformity, primary skin irritation studies and FT-IR studies.Results: The formulated transdermal patch by using Methocel K 100 M showed good physical properties. The average weight of patches prepared using glycerin as a plasticizer were ranged from 42.33-67.00 mg and propylene glycol as a plasticizer were ranged from 40.67-67.67 mg. The percentage moisture absorption varies from 1.76 to 10.73 for patches formulated using glycerin and 2.28 to 7.97 for propylene glycol patches. The percentage moisture loss from patches prepared using glycerin was ranged from 2.75 to 11.54 and 2.87 to 12.02 from propylene glycol. The water vapour transmission rate from patches prepared using glycerin was ranged from 0.25 to 0.92 and 0.41 to 1.76. The formulated patch showed the acceptable quantity of medicament ranged from (100.20-101.05%). This result met the test content uniformity as per BP (85% to 115%). According to that, the drug was consistent throughout the patches. The formulation PGD is considered as the best formulation, since it shows a maximum in vitro drug release as 43.75 % at 24 h. The drug release kinetics studied showed that the majority of formulations was following zero order.Conclusion: In conclusion, controlled release transdermal drug delivery system patches of aliskiren can be prepared using polymer combinations, with a different plasticizer. The release rate of drug depends upon the polymer. However, release kinetics followed zero order.

scholarly journals Spray-Formed Layered Polymer Microneedles for Controlled Biphasic Drug Delivery

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 369 ◽  
Author(s):  
Seok Park ◽  
Min Kim ◽  
Seung-Ki Baek ◽  
Jung-Hwan Park ◽  
Seong-O Choi
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Diffusion Barrier ◽  
Structural Changes ◽  
Tertiary Structure ◽  
Ex Vivo ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Transdermal Drug Delivery System ◽  
Initial Burst

In this study we present polymeric microneedles composed of multiple layers to control drug release kinetics. Layered microneedles were fabricated by spraying poly(lactic-co-glycolic acid) (PLGA) and polyvinylpyrrolidone (PVP) in sequence, and were characterized by mechanical testing and ex vivo skin insertion tests. The compression test demonstrated that no noticeable layer separation occurred, indicating good adhesion between PLGA and PVP layers. Histological examination confirmed that the microneedles were successfully inserted into the skin and indicated biphasic release of dyes incorporated within microneedle matrices. Structural changes of a model protein drug, bovine serum albumin (BSA), in PLGA and PVP matrices were examined by circular dichroism (CD) and fluorescence spectroscopy. The results showed that the tertiary structure of BSA was well maintained in both PLGA and PVP layers while the secondary structures were slightly changed during microneedle fabrication. In vitro release studies showed that over 60% of BSA in the PLGA layer was released within 1 h, followed by continuous slow release over the course of the experiments (7 days), while BSA in the PVP layer was completely released within 0.5 h. The initial burst of BSA from PLGA was further controlled by depositing a blank PLGA layer prior to forming the PLGA layer containing BSA. The blank PLGA layer acted as a diffusion barrier, resulting in a reduced initial burst. The formation of the PLGA diffusion barrier was visualized using confocal microscopy. Our results suggest that the spray-formed multilayer microneedles could be an attractive transdermal drug delivery system that is capable of modulating a drug release profile.

scholarly journals Monitoring of Antimicrobial Drug Chloramphenicol Release from Electrospun Nano- and Microfiber Mats using UV Imaging and Bacterial Bioreporters

Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 487 ◽  
Author(s):  
Preem ◽  
Bock ◽  
Hinnu ◽  
Putrinš ◽  
Sagor ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Bacterial Infections ◽  
High Performance ◽  
Model Systems ◽  
Local Drug Delivery ◽  
Imaging Method ◽  
Release Behavior ◽  
Buffer Solution ◽  
Uv Imaging

New strategies are continuously sought for the treatment of skin and wound infections due to increased problems with non-healing wounds. Electrospun nanofiber mats with antibacterial agents as drug delivery systems provide opportunities for the eradication of bacterial infections as well as wound healing. Antibacterial activities of such mats are directly linked with their drug release behavior. Traditional pharmacopoeial drug release testing settings are not always suitable for analyzing the release behavior of fiber mats intended for the local drug delivery. We tested and compared different drug release model systems for the previously characterized electrospun chloramphenicol (CAM)-loaded nanofiber (polycaprolactone (PCL)) and microfiber (PCL in combination with polyethylene oxide) mats with different drug release profiles. Drug release into buffer solution and hydrogel was investigated and drug concentration was determined using either high-performance liquid chromatography, ultraviolet-visible spectrophotometry, or ultraviolet (UV) imaging. The CAM release and its antibacterial effects in disc diffusion assay were assessed by bacterial bioreporters. All tested model systems enabled to study the drug release from electrospun mats. It was found that the release into buffer solution showed larger differences in the drug release rate between differently designed mats compared to the hydrogel release tests. The UV imaging method provided an insight into the interactions with an agarose hydrogel mimicking wound tissue, thus giving us information about early drug release from the mat. Bacterial bioreporters showed clear correlations between the drug release into gel and antibacterial activity of the electrospun CAM-loaded mats.

scholarly journals Targeted Drug Delivery Systems for the Treatment of Glaucoma: Most Advanced Systems Review

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1742 ◽  
Author(s):  
Olga Cegielska ◽  
Paweł Sajkiewicz
Keyword(s):  
Drug Delivery ◽  
Side Effects ◽  
Targeted Delivery ◽  
Drug Targets ◽  
Drug Delivery Systems ◽  
Release Kinetics ◽  
Controlled Drug Release ◽  
Drug Carriers ◽  
Delivery Systems ◽  
Drug Bioavailability

Each year, new glaucoma drug delivery systems are developed. Due to the chronic nature of the disease, it requires the inconvenient daily administration of medications. As a result of their elution from the eye surface and penetration to the bloodstream through undesired permeation routes, the bioavailability of active compounds is low, and systemic side effects occur. Despite numerous publications on glaucoma drug carriers of controlled drug release kinetics, only part of them consider drug permeation routes and, thus, carriers’ location, as an important factor affecting drug delivery. In this paper, we try to demonstrate the importance of the delivery proximal to glaucoma drug targets. The targeted delivery can significantly improve drug bioavailability, reduce side effects, and increase patients’ compliance compared to both commercial and scientifically developed formulations that can spread over the eye surface or stay in contact with conjunctival sac. We present a selection of glaucoma drug carriers intended to be placed on cornea or injected into the aqueous humor and that have been made by advanced materials using hi-tech forming methods, allowing for effective and convenient sustained antiglaucoma drug delivery.

scholarly journals Near-infrared luminescent CaTiO3:Nd3+ nanofibers with tunable and trackable drug release kinetics

2015 ◽  
Vol 3 (37) ◽  
pp. 7449-7456 ◽  
Author(s):  
Xiang Li ◽  
Qiuhong Zhang ◽  
Zeeshan Ahmad ◽  
Jie Huang ◽  
Zhaohui Ren ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Near Infrared ◽  
Release Kinetics ◽  
Drug Release Kinetics ◽  
Nir Emission ◽  
Delivery Platform

Nd3+ doped CaTiO3 nanostructures serve as a promising drug delivery platform with the potential to monitor drug release kinetics by detecting the tissue-penetrating NIR emission.

scholarly journals Hitchhiking on Controlled-Release Drug Delivery Systems: Opportunities and Challenges for Cancer Vaccines

2021 ◽  
Vol 12 ◽  
Author(s):  
Lu Han ◽  
Ke Peng ◽  
Li-Ying Qiu ◽  
Meng Li ◽  
Jing-Hua Ruan ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Controlled Release ◽  
Immune Responses ◽  
Cancer Vaccines ◽  
Drug Delivery Systems ◽  
Rational Design ◽  
Release Kinetics ◽  
Delivery Systems ◽  
Release Drug ◽  
Multiple Drugs

Cancer vaccines represent among the most promising strategies in the battle against cancers. However, the clinical efficacy of current cancer vaccines is largely limited by the lack of optimized delivery systems to generate strong and persistent antitumor immune responses. Moreover, most cancer vaccines require multiple injections to boost the immune responses, leading to poor patient compliance. Controlled-release drug delivery systems are able to address these issues by presenting drugs in a controlled spatiotemporal manner, which allows co-delivery of multiple drugs, reduction of dosing frequency and avoidance of significant systemic toxicities. In this review, we outline the recent progress in cancer vaccines including subunit vaccines, genetic vaccines, dendritic cell-based vaccines, tumor cell-based vaccines and in situ vaccines. Furthermore, we highlight the efforts and challenges of controlled or sustained release drug delivery systems (e.g., microparticles, scaffolds, injectable gels, and microneedles) in ameliorating the safety, effectiveness and operability of cancer vaccines. Finally, we briefly discuss the correlations of vaccine release kinetics and the immune responses to enlighten the rational design of the next-generation platforms for cancer therapy.

Sign in / Sign up

Export Citation Format

Share Document