Controlled Drug Delivery Vehicles Research Articles

Core-Shell Structure of Photopolymer-Grafted Polyurethane as a Controlled Drug Delivery Vehicle for Biomedical Application.

Functionalized ultraviolet photocurable bisphenol A-glycerolate dimethacrylates with tailorable size have been synthesized as the core, which have further been grafted using the diisocyanate chain end of polyurethane (PU) as the shell to create a core-shell structure of tunable size for a controlled drug delivery vehicle. The core-shell structure has been elucidated through spectroscopic techniques like 1H NMR, FTIR, and UV-vis and their relative shape and size through TEM and AFM morphology. The greater cross-link density of the core is reflected in the higher glass transition temperature, and the improved thermal stability of the graft copolymer is proven from its thermogravimetric analyses. The flow behavior and enhanced strength of the graft copolymers have been revealed from rheological measurements. The graft copolymer exhibits sustained release of the drug, as compared to pure polyurethane and photopolymer, arising from its core-shell structure and strong interaction between the copolymer and drug, as observed through a significant shifting of absorption peaks in FTIR and UV-vis measurements. Biocompatibility has been tested for the real application of the novel graft copolymer in medical fields, as revealed from MTT assay, cell imaging, and cell adhesion studies. The efficacy of controlled release from a graft copolymer has been verified from the gradual cell killing and ∼70% killing in 3 days vs meager cell killing of ∼25% very quickly in 1 day, followed by the increased cell viability of the system treated with the pure drug. The mechanism of slow and controlled drug release from the core-shell structure has been explored. The fluorescence images support the higher cell-killing efficiency as opposed to a pure drug or a drug embedded in polyurethane. Cells seeded on 3D scaffolds have been developed by embedding a graft copolymer, and fluorescence imaging confirms the successful growth of cells within the scaffold, realizing the potential of the core-shell graft copolymer in the biomedical arena.

Novel pH-sensitive gum ghatti-cl-poly(acrylic acid) composite hydrogel based on graphene oxide for metformin hydrochloride and sodium diclofenac combined drug-delivery systems

The results showed that the mixtures of synthetic hydrogels might be utilised as potential agents for controlled drug delivery vehicles.

Polyanhydride Chemistry.

Polyanhydrides (PAs) are a class of synthetic biodegradable polymers employed as controlled drug delivery vehicles. They can be synthesized and scaled up from low-cost starting materials. The structure of PAs can be manipulated synthetically to meet desirable characteristics. PAs are biocompatible, biodegradable, and generate nontoxic metabolites upon degradation, which are easily eliminated from the body. The rate of water penetrating into the polyanhydride (PA) matrix is slower than the anhydride bond cleavage. This phenomenon sets PAs as "surface-eroding drug delivery carriers." Consequently, a variety of PA-based drug delivery carriers in the form of solid implants, pasty injectable formulations, microspheres, nanoparticles, etc. have been developed for the sustained release of small molecule drugs, and vaccines, peptide drugs, and nucleic acid-based active agents. The rate of drug delivery is often controlled by the polymer erosion rate, which is influenced by the polymer structure and composition, crystallinity, hydrophobicity, pH of the release medium, device size, configuration, etc. Owing to the above-mentioned interesting physicochemical and mechanical properties of PAs, the present review focuses on the advancements made in the domain of synthetic biodegradable biomedical PAs for therapeutic delivery applications. Various classes of PAs, their structures, their unique characteristics, their physicochemical and mechanical properties, and factors influencing surface erosion are discussed in detail. The review also summarizes various methods involved in the synthesis of PAs and their utility in the biomedical domain as drug, vaccine, and peptide delivery carriers in different formulations are reviewed.

Synthesis of Alginate/Hydroxyapatite Beads for Acetaminophen Delivery

Conventional drug delivery systems usually involve the intake of multiple drugs, which could amplify the risk of overdosing. Acetaminophen is a widely used pain relief substance that is prone to accidental overdosing. Hence, a controlled drug delivery system is needed to ensure its efficacy. A nanocomposite hydroxyapatite/alginate system that was used as a drug carrier for acetaminophen was synthesized through the sol-gel method, and the mechanism underlying its controlled drug delivery was investigated. Spherical nanocomposite bead samples were synthesized by incorporating 5 wt%, 10 wt%, and 15 wt% hydroxyapatite into mixtures containing alginate. The mixtures were then dropped into calcium chloride solution. The phase purity of the hydroxyapatite sample was confirmed through X-ray diffraction, and the functional groups that confirmed the presence of alginate and hydroxyapatite in the nanocomposite samples were analyzed by using Fourier transform infrared spectroscopy. The release of acetaminophen can be controlled for 48 h, and the Korsmeyer–Peppas kinetics model showed the best correlation for all samples. The kinetics of Al/HAp5, Al/HAp10, and Al/HAp15 were governed by quasi-Fickian diffusion with the n values of 0.199, 0.238, and 0.225, respectively. The composite beads show potential for application as a controlled drug delivery vehicle.

Preparation of carrageenan/ chitosan-based (N,N,N-trimeth(yl chitosan chloride) silver nanocomposites as pH sensitive carrier for effective controlled curcumin delivery in cancer cells

PurposeThis work aims to formulate a novel pH-sensitive biocompatible metallic nanocomposite as a carrier for hydrophobic drugs with efficient loading and controlled drug release. The proposed carrier consists of a polyelectrolyte complex of chitosan-based, N,N,N-trimethyl chitosan chloride (TMC), and carrageenan (CAR) biopolymers with different silver nanoparticles (AgNPs) molar ratios forming CAR/TMC-Ag nanocomposites that investigated to be used as a carrier for controlled gastro-intestinal tract (GIT) release of curcumin (CUR) as a model of lipophilic drugs. MethodsThe structure of nanocomposites was scrutinized via FTIR, TEM, SEM, XRD and EDX, whereas the potential cytotoxicity and antimicrobial efficacy of loaded nanocomposite with 3% AgNPs (NC-3% Ag) were probed, as well. ResultsSuccessful loading and release of CUR were detected from the prepared nanocomposites without change in its functionality with a higher releasing profile in pH 7.4 (simulated intestinal fluid) than pH 1.2 (simulated gastric fluid). In vitro release study of CUR loaded NC-3% Ag showed the favored sustained drug release reaching 98.9% ± 0.9 within 24 h in pH 7.4, following Korsmeyer−Peppas model. Additionally, successful release from loaded CAR/TMC nanocomposite with 3% AgNPs (NC-3% Ag), revealed high cytotoxic effect with apoptotic induction against human colon cancerous cells (Caco-2) through G2/M cell cycle arrest and antibacterial potency against different bacterial strains. Moreover, cell viability results of NC-3% Ag against human normal cells exhibited good biocompatibility. ConclusionAccordingly, we suggested NC-3% Ag as a promising controlled drug delivery vehicle for hydrophobic drugs with preferred intestinal targeting effectiveness.

Microfluidic Synthesis of Indomethacin-Loaded PLGA Microparticles Optimized by Machine Learning.

Several attempts have been made to encapsulate indomethacin (IND), to control its sustained release and reduce its side effects. To develop a successful formulation, drug release from a polymeric matrix and subsequent biodegradation need to be achieved. In this study, we focus on combining microfluidic and artificial intelligence (AI) technologies, alongside using biomaterials, to generate drug-loaded polymeric microparticles (MPs). Our strategy is based on using Poly (D,L-lactide-co-glycolide) (PLGA) as a biodegradable polymer for the generation of a controlled drug delivery vehicle, with IND as an example of a poorly soluble drug, a 3D flow focusing microfluidic chip as a simple device synthesis particle, and machine learning using artificial neural networks (ANNs) as an in silico tool to generate and predict size-tunable PLGA MPs. The influence of different polymer concentrations and the flow rates of dispersed and continuous phases on PLGA droplet size prediction in a microfluidic platform were assessed. Subsequently, the developed ANN model was utilized as a quick guide to generate PLGA MPs at a desired size. After conditions optimization, IND-loaded PLGA MPs were produced, and showed larger droplet sizes than blank MPs. Further, the proposed microfluidic system is capable of producing monodisperse particles with a well-controllable shape and size. IND-loaded-PLGA MPs exhibited acceptable drug loading and encapsulation efficiency (7.79 and 62.35%, respectively) and showed sustained release, reaching approximately 80% within 9 days. Hence, combining modern technologies of machine learning and microfluidics with biomaterials can be applied to many pharmaceutical applications, as a quick, low cost, and reproducible strategy.

Rutin: a Flavonoid Precursor for Synthesis of ZnFe2O4 Nanoparticles; Electrochemical Study of Zinc Ferrite-chitosan Nanogel for Doxorubicin Delivery

The use of core-shell nanoparticles as controlled drug delivery vehicles has proven successful, yet their production and application require costly and toxic chemicals. We hereby use a natural glycosylated flavonoid (rutin) for synthesis of a nanocarrier for doxorubicin delivery. For this target, a convenient two-step synthesis was processed including a synthesis of bio-zinc ferrite nanoparticles without N2 gas and chitosan coating (CS; bio-zincferrite@chitosan). The as-synthesized magnetic nanogel was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transformed infrared (FT-IR) spectroscopy, and electro-analytical methods including cyclic voltammetry and electrochemical impedance spectroscopies. The collapse/swell potential of the coated CS layers of the bio-NPs were found to be responsible for the observed pH dependence of doxorubicin delivery. Results exhibited the drug release of bio-nanogel can be induced at pH ranging from 6 to 7. Therefore, capacity and efficiency parameters of the anti-cancer drug onto the NPs were obtained as equal to 43.5% and 78.6%. The present work provides a simple method to fabricate smart pH-responsive nanogel for cancer therapy.

Polypropylene oxide/polyethylene oxide‐cellulose hybrid nanocomposite hydrogels as drug delivery vehicle

AbstractThis article deals with the synthesis of hybrid nanocomposite hydrogels through the combination of cellulose (C), polypropylene oxide/poly ethylene oxide (PPO/PEO), and silver nanoparticles (AgNPs) by in situ polymerization technique for the in vitro release of ornidazole drugs. The structure of the resulted materials is identified using SEM, XRD, FTIR, XPS, and TGA spectroscopic techniques. The resulting structure, morphology, thermo responsive property, water retention, and swelling behavior of hydrogels are investigated. The rheological measurement is studied to establish the enhancement of the viscoelasticity and stiffness of hydrogels. The antibacterial activity of the biodegradable silver hybrid nanocomposite hydrogel is investigated by inhibition zone method against gram positive and negative bacteria. Maximum drug release of 96.4% is recorded at 7.4 pH in 5 h. The biocompatibility and cytotoxicity of the hybrid nanocomposite hydrogel are verified using mouse fibroblast cell line L‐929 (ATCC CCL‐1) cells for their possible use as controlled drug delivery vehicles. The nontoxic nature makes the materials more biocompatible and suitable to apply in the biological systems. Therefore, nontoxic and biocompatible natures of present materials with improved thermal and rheological properties support for their possible uses as drug delivery vehicles.

Antioxidant-mediated control of degradation and drug release from surface-eroding poly(ethylene carbonate)

Surface-eroding polymers are of significant interest for various applications in the field of controlled drug delivery. Poly(ethylene carbonate), as an example, offers little control over the rate of degradation and, thus, drug release, which usually conflicts with the requirements for long-acting medications.Here, we challenged an option to decelerate the degradation of poly(ethylene carbonate) in vitro and in vivo. When polymer films loaded with distinct antioxidants (vitamins) along with the model drugs leuprorelin and risperidone were incubated in superoxide radical solution and phagocyte culture, the mass loss and drug release from the delivery vehicle was a function of the type and dose of the utilized antioxidant. Once the polymer surface was “attacked” by reactive oxygen species, the antioxidants were released on demand quenching the polymer-degrading radicals. Accordingly, specific combinations of polymer and radical scavengers resulted in controlled release medications with an extended “life-time” of one month or longer, which is difficult to achieve for poly(ethylene carbonate) in the absence of antioxidants. A comparable degradation and drug release behavior was observed when antioxidant-loaded poly(ethylene carbonate) films were implanted in rats. Furthermore, linear correlations were obtained between the mass loss of the polymer films and the released fraction of drug (with slopes close to 1), a clear indication for the surface erosion of poly(ethylene carbonate) in vitro and in vivo.Overall, an addition of antioxidants to poly(ethylene carbonate)-based controlled drug delivery vehicles represents a reasonable approach to modify the performance of long-acting medications, especially when a “life time” of weeks to months needs to be achieved. Statement of SignificanceSurface-eroding poly(ethylene carbonate) (PEC) is of significant interest for long-acting injectable formulations. However, PEC offers only little control over the rate of degradation and, thus, drug release kinetics. We describe an option to decelerate the degradation rate of PEC in vitro and in vivo. When polymer films loaded with distinct antioxidants along with model drugs were incubated in superoxide radical solution, phagocyte culture and implanted in rats, their mass loss and drug release was a function of the type and dose of the utilized antioxidant. Accordingly, specific combinations of polymer and radical scavengers resulted in controlled release medications with an extended “life-time” of one month or longer, which is difficult to achieve for PEC in the absence of antioxidants.

Controlled Drug Delivery Vehicles in Veterinary Oncology: State-of-the-Art and Future Directions

Controlled drug delivery systems can be used to carry several anticancer agents, including classical chemotherapeutic agents such as doxorubicin, paclitaxel or cisplatin, and are also used for the encapsulation of tyrosine kinase inhibitors and monoclonal antibodies. Usually, the controlled systems are used to decrease drug toxicity, increase local drug concentration or target specific organs or systems. In dogs, liposomal doxorubicin is the most known controlled drug delivery vehicle in veterinary medicine. However, several antitumor drugs can be encapsulated within these systems. Since the delivery vehicles are a relatively new topic in veterinary oncology, this review aims to discuss the current knowledge regarding the controlled drug delivery vehicles and discuss the current challenges and future direction of its use in veterinary oncology.

Injectable Hydrogel through Hydrophobic Grafting on Chitosan for Controlled Drug Delivery.

An injectable hydrogel of chemically modified chitosan has been developed for controlled drug delivery application. Highly hydrophilic chitosan is chemically modified through grafting of ester-diol based polyurethane to transform into hydrogel through hydrophilic-hydrophobic balance. Grafting is confirmed through different spectroscopic techniques such as 13C NMR, UV-visible, and FTIR. Grafted copolymer shows higher contact angle as well as poorer swelling than pure one. Hydrogel of graft copolymer is made in dilute acetic acid medium. Surface morphology of the hydrogel, as investigated through SEM, exhibits an interconnected porous network suitable for drug delivery vehicle. In vitro drug release kinetics reveals that the graft copolymer releases the drug in a sustained manner as compared to the pure one. Two types of model drugs (antibacterial tetracycline hydrochloride and anticancerous doxorubicin hydrochloride) are used for release study to check the control release for various applications. The cytotoxicity of the newly developed hydrogel is accessed using the B16-F10 melanoma cell line, and the hydrogel is found to have a better biocompatible nature than that of pure chitosan. Cellular uptake of drug from graft copolymer hydrogel has considerably increased vis-à-vis pure drug resulting in significant enhancement of cell killing using the developed drug embedded hydrogel system. In vivo gelation study in an animal model verifies that the graft copolymer has the fine ability to be used as an injectable hydrogel for disease control. Hence, the developed graft copolymer has the potential to be used as an injectable hydrogel as a controlled drug delivery vehicle.

Nanohybrid Scaffold of Chitosan and Functionalized Graphene Oxide for Controlled Drug Delivery and Bone Regeneration.

Nanohybrid scaffolds of chitosan have been designed for controlled drug delivery and bone regeneration. Sulfonated graphene oxide has been used to develop the nanohybrids. Nanohybrid scaffolds show highly hydrophilic character and greater mechanical strength as compared to pure chitosan. Nanohybrid scaffolds show an interconnected uniform porous network structure exhibiting sustained release kinetics of the antibacterial drug, tetracycline hydrochloride. Nanohybrids are found to be highly biocompatible in nature and are able to support and proliferate MG63 osteoblast cells and thereby induce bone tissue regeneration. The in-vivo bone healing study shows that the developed nanohybrid scaffolds have the potential to regenerate the bone faster without any side effects as compared to pure scaffolds. Hence, the developed nanohybrid scaffold has good potential as a controlled drug delivery vehicle and in bone tissue engineering for faster healing.

Cytotoxicity assessment of mesoporous silica nanoparticles -curcumin against breast and colon cancer cell lines: in vitro study

Curcumin is one of the most promising natural anticancer agents, however, its medical application has been limited by its poor water solubility and bioavailability. Attempts have been made to encapsulate curcumin in different carriers, but the interest in nanocarriers for cancer chemotherapy is growing to develop a biodegradable controlled drug delivery vehicle that improves the bioavailability and solubility of curcumin. Here we focused on designing a biocompatible delivery system to be used as nanocarrier of the natural anticancer curcumin allowing its application either in vitro or in vivo. Therefore, mesoporous silica was prepared as a nanocarrier for curcumin. Characterization of the prepared nanocarriers was investigated using different techniques. Transmission electron microscopy (TEM) revealed the spherical, smooth surface of the nano-formulation. Dynamic light scattering (DLS) was used for measuring the hydrodynamic size of the prepared nanocarrier. The stability was also studied by zeta potential measurement indicating its high stability. Fourier transform infrared spectroscopy (FTIR) assessment revealed that curcumin was successfully loaded into mesoporous nanoparticles. In vitro studies elucidated that curcumin loaded nanoparticles have a more potent therapeutic effect than free curcumin against both HCT-116 and MCF-7 cancer cells. The nanocarrier can provide high therapeutic efficacy represented by the inhibition of cancer cells proliferation. Therefore, the development of such novel curcumin nanocarrier with its better curative effect will bring the nutraceutical nanoformulation to be an alternative to the chemotherapeutic drugs.

Recent progress in nanoscale metal-organic frameworks for drug release and cancer therapy.

Nanoscale metal-organic frameworks (MOFs) have been widely used as controlled drug delivery vehicles and cancer therapy agents due to their intrinsic superior properties. Scientists have made remarkable achievements in the field of nanomedicine by using the MOFs and MOF-based multifunctional nanomaterials due to the easy synthesis into nanoscale and functionalization. In this review, we highlight the recent progress of nanoscale MOFs as drug delivery vehicles for cancer theranostics. We divide the discussion into three parts. The first and second parts focus on the drug delivery of unmodified MOF and modified MOFs, respectively, while the third part focuses on porphyrin MOFs as photosensitizers for photodynamic therapy. Finally, we conclude by identifying areas of research that we believe will propel the translation and application of MOFs.

Nanoparticle-Induced Controlled Drug Delivery Using Chitosan-Based Hydrogel and Scaffold: Application to Bone Regeneration.

The novel chitosan nanohybrid hydrogel and scaffold have been developed with high mechanical strength and tailor the drug release ability for their applications in the biomedical arena. Nanohybrid hydrogels are prepared in dilute acetic acid medium using two different types of two-dimensional-layered nanoparticles. Scaffolds are prepared through lyophilization of hydrogels. Highly porous, open, and 3D interconnected morphologies are observed in the nanohybrid scaffolds, as opposed to the thick wall, smaller pore dimension in pure chitosan. The interaction between the nanoparticles and chitosan chains are elucidated using different spectroscopic techniques, which in turn are responsible for the uniform distribution of the nanoparticle in the chitosan matrix. Nanohybrids are found to be highly mechanically stable in both states (hydrogel and scaffold), as compared to pure chitosan because of the good reinforcing ability of 2D nanoparticles. Sustained drug release has been achieved in nanohybrid in vitro, as compared to the pure chitosan hydrogel/scaffold, mainly due to greater interactions between the components and the better barrier effect of 2D nanoparticles. Cytotoxicity of the nanohybrids is verified using NIH 3T3 mouse embryonic fibroblast cells for their possible use as controlled drug delivery vehicles. Nanohybrids are found to be nontoxic in nature and more biocompatible as compared to pure chitosan, as observed through cell viability and cell imaging studies. Interestingly, cell growth occurs within the pores of the nanohybrid scaffold, vis-à-vis the surface proliferation noticed in the pure chitosan scaffold. Better biocompatibility, hydrophilic nature, and sustained delivery with location specific cell growth make this nanohybrid hydrogel unique for biomedical uses. The bone regeneration rate is found to be significantly higher for the nanohybrid scaffold as compared to blank/pure chitosan without any side effect, suggesting nanohybrid systems are superior biomaterials.

Controlled drug delivery vehicles for cancer treatment and their performance

Although conventional chemotherapy has been successful to some extent, the main drawbacks of chemotherapy are its poor bioavailability, high-dose requirements, adverse side effects, low therapeutic indices, development of multiple drug resistance, and non-specific targeting. The main aim in the development of drug delivery vehicles is to successfully address these delivery-related problems and carry drugs to the desired sites of therapeutic action while reducing adverse side effects. In this review, we will discuss the different types of materials used as delivery vehicles for chemotherapeutic agents and their structural characteristics that improve the therapeutic efficacy of their drugs and will describe recent scientific advances in the area of chemotherapy, emphasizing challenges in cancer treatments.

3D printed liner for treatment of periprosthetic joint infections

In the United States, long standing deep infections of joint arthroplasty, such as total knee and total hip replacements, are treated with two-stage exchange. This requires the removal of the prior implant, placement of an antibiotic eluting spacer block made of polymethylmethacrylate (PMMA), followed by re-implantation of a new implant after treatment with intravenous antibiotics for six to eight weeks. Unfortunately, the use of PMMA as a spacer material has limitations in terms of mechanical and drug-eluting properties. PMMA is brittle and elutes most of the antibiotics within the first few days. Furthermore, the polymerization reaction for PMMA is highly exothermic, thereby limiting the use to heat-stable antibiotics. We hypothesize that the use of a 3D printed polymeric liner made of polylactic acid (PLA) would overcome the limitations of PMMA because it is a stronger and a less brittle material than PMMA. Furthermore, the liner can also act as a controlled drug delivery vehicle by using built in reservoirs and a network of micro-channels as well as by incorporating antibiotics directly into the polymer during manufacturing stage. Finally, the liner can be 3D printed according to the anatomy of the patient and thereby has the potential to transform the manner in which periprosthetic joint infections are currently treated.

Biodegradable poly(ε-caprolactone) as a controlled drug delivery vehicle of vancomycin for the treatment of MRSA infection.

Biodegradable poly(ε-caprolactone) (PCL) is developed as a controlled drug delivery vehicle of vancomycin (VMC) with the advantage of avoiding a second surgery. The PCL-VMC hybrid, prepared through a solution route, is used as a delivery vehicle for vancomycin for controlling MRSA osteomyelitis as well as healing the cavity simultaneously in an experimental study. An in vitro study is conducted to optimize vancomycin impregnation in the PCL-VMC hybrid. An in vitro study on drug release from the hybrid material is investigated in phosphate buffer saline showing steady and sustained release of the drug. The release kinetics is fitted with several models and a non-Fickian nature is established following the Korsmeyer-Peppas model. Spectroscopic techniques and morphology observations reveal the cause of sustained release to be the strong interaction between the drug and the polymer. The results of the antibacterial assay show that the loading of vancomycin into the PCL matrix is able to maintain the activity of the pure drug. For the in vivo study, a unicortical defect is created in the metaphysis of the distal femur in rabbits. After contaminating the defect with MRSA, the 1st group of rabbits were treated with pure polymer, the 2nd group of rabbits were treated with normal saline (PBS), the 3rd group of rabbits were treated with pure VMC and in the last group of rabbits PCL-VMC was placed. Rabbits are assessed by clinical, radiological, histological, gross examination and bacterial load assays. Infection persisted throughout the period of study for both the pure polymer and PBS treated rabbits while rabbits treated with the PCL-VMC hybrid do not show any sign of infection. The VMC treated group rabbits show mild infection for the 1st week of the study; however, the infection becomes gradually more severe with time. Serial histology confirms the formation of new bone without any inflammation and necrosis for the rabbits treated with PCL-VMC. Importantly, the PCL-VMC hybrid bioadsorbs after delivery of the drug and thereby avoids the second surgery to remove the conventional implant.

Graphene as a chain extender of polyurethanes for biomedical applications

Chemically tagged graphene nanohybrid for a controlled drug delivery vehicle.

Highly biocompatible behaviour and slow degradation of a LDH (layered double hydroxide)-coating on implants in the middle ear of rabbits.

Chronic inflammation can irreversibly damage components of the ossicular chain which may lead to sound conduction deafness. The replacement of impaired ossicles with prostheses does not reduce the risk of bacterial infections which may lead to loss of function of the implant and consequently to additional damage of the connected structures such as inner ear, meninges and brain. Therefore, implants that could do both, reconstruct the sound conduction and in addition provide antibacterial protection are of high interest for ear surgery. Layered double hydroxides (LDHs) are promising novel biomaterials that have previously been used as an antibiotic-releasing implant coating to curb bacterial infections in the middle ear. However, animal studies of LDHs are scarce and there exist only few additional data on the biocompatibility and hardly any on the biodegradation of these compounds. In this study, middle ear prostheses were coated with an LDH compound, using suspensions of nanoparticles of an LDH containing Mg and Al as well as carbonate ions. These coatings were characterized and implanted into the middle ear of healthy rabbits for 10 days. Analysis of the explanted prostheses showed only little signs of degradation. A stable health constitution was observed throughout the whole experiment in every animal. The results show that LDH-based implant coatings are biocompatible and dissolve only slowly in the middle ear. They, therefore, appear as promising materials for the construction of controlled drug delivery vehicles.