Specific Drug Delivery System Research Articles

Additive manufacturing: a bespoke solution for drug delivery

PurposeAdditive manufacturing (AM), also known as three-dimensional (3D) printing technology, has been used in the health-care industry for over two decades. It is in high demand in the health-care industry due to its strength to manufacture custom-designed and personalized 3D constructs. Recently, AM technologies are being explored to develop personalized drug delivery systems, such as personalized oral dosages, implants and others due to their potential to design and develop systems with complex geometry and programmed controlled release profile. Furthermore, in 2015, the US Food and Drug Administration approved the first AM medication, Spritam® (Apprecia Pharmaceuticals) which has led to tremendous interest in exploring this technology as a bespoke solution for patient-specific drug delivery systems. The purpose of this study is to provide a comprehensive overview of AM technologies applied to the development of personalized drug delivery systems, including an analysis of the commercial status of AM based drugs and delivery devices.Design/methodology/approachThis review paper provides a detailed understanding of how AM technologies are used to develop personalized drug delivery systems. Different AM technologies and how these technologies can be chosen for a specific drug delivery system are discussed. Different types of materials used to manufacture personalized drug delivery systems are also discussed here. Furthermore, recent preclinical and clinical trials are discussed. The challenges and future perceptions of personalized medicine and the clinical use of these systems are also discussed.FindingsSubstantial works are ongoing to develop personalized medicine using AM technologies. Understanding the regulatory requirements is needed to establish this area as a point-of-care solution for patients. Furthermore, scientists, engineers and regulatory agencies need to work closely to successfully translate the research efforts to clinics.Originality/valueThis review paper highlights the recent efforts of AM-based technologies in the field of personalized drug delivery systems with an insight into the possible future direction.

Nanosponges: A Targeted Drug Delivery System

The latest advances in nanotechnology have resulted in the development of a targeted drug delivery system. However, in order to efficiently target a molecule to a specific place with a drug delivery system, a specialized drug delivery system is required. The discovery of nanosponge has been a big step toward overcoming challenges such as drug toxicity, low bioavailability, and predictable drug release because they can accept both hydrophilic and hydrophobic drugs. Nanosponges, a newly developed colloidal system, have the potential to address concerns such as medicine toxicity, lower bioavailability, and drug release over a large region because they can be adjusted to operate with both hydrophilic and hydrophobic pharmaceuticals. Nanosponges are small structures with a three-dimensional network and porous hollow. Nanosponges are small structures with a three-dimensional network and porous hollow. They can be easily created by crosslinking cyclodextrins with various chemicals. Because of Cyclodextrin's excellent biocompatibility, stability, and safety, a number of Cyclodextrin-based drug delivery systems have been rapidly developed. The nanosponge drug delivery system has a wide range of applications, including cancer, autoimmune illnesses, theranostic uses, increased bioavailability, and stability. This review delves into the benefits and downsides, preparation procedures, factors influencing their preparation, characterisation techniques, applications, and the most recent advancements in nanosponges. Nanosponges can also act as an efficient carrier of enzymes, proteins, vaccines, and antibodies. The current review focuses on the method of preparation, characterisation, and possible application in drug delivery systems.

Formulation characterization of lecithin organogel as topical drug delivery system for psoriasis: In-vitro permeation and preclinical evaluation.

Psoriasis is a chronic inflammatory and proliferative skin disease that causes pathological skin changes and has a substantial impact on the quality of patient life. Apremilast was approved by the US Food and Drug Administration as an oral medication for psoriasis and is beneficial in mild to moderate conditions for chronic usage. However, 5%-7% of withdrawals were reported due to severe side effects. To address the issue, a localized drug delivery strategy via the topical route may be a viable approach. However, poor physicochemical properties make it vulnerable to passing through the skin, requiring a specialized drug delivery system to demonstrate its full potential via a topical route like lecithin organogel. The formulation was optimized by screening the suitable lecithin type and non-polar solvents based on the gel formation ability of lecithin and the solubility of apremilast in the solvent. The pseudo-ternary diagram was used to optimize the water content required to form the gel. The optimized gel was found to be shear thinning characterized for rheological parameters, in-vitro diffusion studies, and in-vitro skin distribution studies. Preclinical studies in Imiquimod-induced mice showed a better reduction in severity index, cytokine levels, and epidermal hyperplasia from the lecithin organogel group compared to the apremilast oral administration and marketed standard topical gel group. Based on these results, lecithin organogel can be considered a promising approach to deliver molecules like apremilast by topical route in psoriatic-like conditions.

Cluster of Differentiation-44-Targeting Prussian Blue Nanoparticles Onloaded with Colchicine for Atherosclerotic Plaque Regression in a Mice Model.

Atherosclerosis management heavily relies on the suppression of the inflammatory response of macrophages. Colchicine's potent anti-inflammatory properties make it a promising candidate for secondary prevention against cardiovascular disease. However, its high toxicity and numerous adverse effects limit its clinical use. To address this, there is an urgent need for specific drug delivery systems to boost the level of accumulation of colchicine within atherosclerotic plaques. In this study, the cluster of differentiation-44 receptor was verified to be overexpressed in inflammatory macrophages within plaques both in vitro and in vivo. Subsequently, a Prussian blue-based nanomedical loading system with hyaluronic acid (HA) coating was constructed, and its effects were observed on the atherosclerosis regression. Colchicine and Cy5.5 were encapsulated within Prussian blue nanoparticles through self-assembly, followed by conjugation with hyaluronic acid to create col@PBNP@HA. The formulated col@PBNP@HA displayed a cubic shape and scattered distribution. Importantly, col@PBNP@HA demonstrated specific cellular uptake into lipopolysaccharide-stimulated macrophages. In vitro experiments showed that col@PBNP@HA more effectively inhibited expression of inflammatory factors and scavenged reactive oxygen species compared with the control group, which were treated with colchicine. Furthermore, col@PBNP@HA exhibited its specific and higher accumulation in aortic plaque analysis via fluorescence imaging of aortas. After 4 weeks, administration of col@PBNP@HA resulted in significant atherosclerosis regression in the mice model, with therapeutic effects superior to those of free colchicine. Similar to colchicine, col@PBNP@HA inhibited the secretion of inflammation factors and scavenged ROS through the regulation of the toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (Myd88)/nuclear factor kappa-B (NF-κB) and peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) signaling pathway. In summary, col@PBNP@HA demonstrated specific targeting ability to inflammatory plaques and exerted beneficial effects on atherosclerosis regression through TLR4/Myd88/NF-κB and PGC-1α modulation.

Preparation and in-vitro evaluation of single and bi-layered beeswax-based microparticles for colon-specific delivery of mesalamine

Beeswax is selected as a natural coating material for the development of new colon specific drug delivery systems charged by mesalamine. In a first step, beeswax microparticles are prepared using hot-melt process of microencapsulation where drug:beeswax ratio, stirring speed, emulsifier concentration and pH of external phase are varied for the optimization of the drug entrapment and microparticles? morphology. The effect of the nature of the emulsifier is also discussed by studying the hydrophilic?lipophilic balance (HLB) value. In a second step, to obtain delayed delivery systems, bi-layered microspheres are elaborated by the process of emulsion?solvent evaporation using ethylcellulose or cellulose acetate butyrate as outer enteric coating layer. All formulations are characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy and optical microscopy. The drug release is established in simulated gastric, small bowel and colon liquids and the release mechanism is discussed by applying the Korsmeyer?Peppas model.

Characterization of hydroxypropylated cassava and potato starches: Functional and physicotechnical properties

Introduction: Starch modification is achieved using physical and chemical means to improve the physicochemical characteristics and stability of the molecule with potential applications in specialized drug delivery systems. Purpose: This study aimed to characterize cassava and potato starches modified via hydroxypropylation. Methods: Native cassava and potato starches were subjected to initial pre-gelatinization before being hydroxypropylated (HP) using propylene oxide. The native and HP-starch powders were characterized for their physicochemical properties, powder properties as well as high-resolution analyses using differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Results: Organoleptic evaluations indicated that native starches were white and smooth while HP-starches were off-white, coarse and glassy. The HP-cassava and potato starches significantly increased in solubility by 79.4 and 14.7%, respectively. The HP-starches also exhibited a reduction in the volume of sedimentation, while only the HP-cassava starch showed a reduced water retention capacity of 1.7133 g/g. Percentage syneresis was lower in both HP-cassava and potato starches with 4.16 and 1.08%, respectively. The HP-cassava and potato starches showed excellent flowability with corresponding Carr’s indices of 5.96 and 5.23% and angles of repose of 19.98 and 20.50°, respectively. DSC and FTIR results confirmed starch modification while SEM showed smooth flat particles. Conclusion: Hydroxypropylation enhanced the solubility, reduced the volume of sedimentation and improved the freeze-thaw stability of the native starches. It also increased the water retention capacity and moisture sorption of potato starch.

Advancements and Application of 4D Printing in the Medical Field : A Comprehensive Review

4D printing is an innovative and quickly expanding technology that combines the concepts of 3D printing with the adition of shape –shifting and self adaptable capabilities. The review paper investigates the advancement application of 4 D printing with the medical industry .we describe the fundamental concepts of 4D printing stressing its potential in the production of personalised patient –specific medical equipment tissue engineering drug delivery system and surgical tools. Additionally we evaluate the challenges and future possibility of 4D printing in healthcare.

Abstract C107: INTASYL™ self-delivering RNAi therapeutic targeting BRD4 elicits on-target apoptosis of human tumor cells

Abstract Background: A wealth of preclinical data supports the therapeutic potential of targeting bromodomain and extra-terminal motif (BET) protein BRD4 as a promising strategy to treat a spectrum of cancers. However, clinical translation of BRD4 inhibitors (BRD4i) has not yet been achieved. While clinical trials for next generation small molecule BRD4i compounds are ongoing, such systemic approaches must overcome a narrow therapeutic window. Therefore, a local approach to BRD4i represents a potential strategy to realize its therapeutic potential in injectable solid tumor indications. INTASYL™ is a self-delivering RNAi platform technology that enables rapid and efficient delivery into target cells without need for specialized drug delivery systems or formulations. INTASYL compounds provide precise and durable gene silencing. In preclinical studies, INTASYL compounds provided a robust direct, abscopal and/or anti-metastatic antitumor efficacy when administered intratumorally (IT) as monotherapy, multi-targeting formulations, or in combination with current standard of care treatments. PH-894 is an INTASYL compound designed to specifically silence human BRD4 mRNA. We assessed the direct on-target antitumor effects of PH-894 across a spectrum of human tumor cell lines: HepG2 (hepatocellular carcinoma), HCC1806 (acantholytic squamous cell carcinoma), A549 (lung adenocarcinoma), U-251 MG (malignant glioblastoma), SK-MEL-5 (melanoma), HT-29 (colorectal adenocarcinoma), SK-OV-3 (ovarian adenocarcinoma), HeLa (cervical adenocarcinoma). Methods: Tumor cells were cell-cycle synchronized by serum starvation for ~18 h and treated in the presence of serum with increasing concentrations of PH-894 or a non-targeting control (NTC) INTASYL for 24 h. Apoptosis was assessed by annexin-v and 7-aminoactinomycin D (7AAD) staining/flow cytometry. On-target silencing of BRD4 mRNA by PH-894 was confirmed at 24 h by qPCR. Results: PH-894 elicited on-target apoptosis in all tumor cell lines tested in a concentration correlated manner, with variable levels of response across the various tumor cell lines. BRD4 mRNA was specifically silenced on-target in a concentration correlated manner with PH-894. Conclusions: This study demonstrates the direct cytotoxic effects of INTASYL PH-894 mediated by sequence specific silencing of BRD4 mRNA across tumor cell lines representing a broad spectrum of injectable solid tumors. Local therapy with IT PH-894 represents a potential strategy to mitigate toxicities associated with systemic BETi or BRD4i. This study supports further development of PH-894 toward unlocking the therapeutic potential of BRD4i. Citation Format: Andrew Boone, Dingxue Yan, Melissa Maxwell, Brianna Rivest, James Cardia, Benjamin Cuiffo. INTASYL™ self-delivering RNAi therapeutic targeting BRD4 elicits on-target apoptosis of human tumor cells [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C107.

Efficacy of triple targeted therapy against chronic rhinosinusitis in children with cystic fibrosis (case series)

Introduction. Chronic rhinosinusitis (CRS) with underlying cystic fibrosis (CF) is one of the most challenging inflammatory diseases of the paranasal sinuses (PNS). The treatment of CF in general and CF-associated CRS in particular keeps developing exponentially: special drug delivery systems have been invented, drugs purpose-developed for the treatment of patients with CF (dornase alfa) are used, and radicality of surgical intervention is increasing. In recent years, CF innovative targeted therapy has been introduced. It aims to improve the course of the bronchopulmonary infectious and inflammatory process, nutritional status and pancreatic function, but its efficacy in relation to the PNS condition is still insufficiently studied.Aim. To evaluate the efficacy of ivacaftor/elexacaftor/tezacaftor therapy for CF sinonasal manifestations in children and to determine possible parallels of the CRS course vs other characteristics of the CF course.Materials and methods. A total of 15 children with CF receiving triple targeted therapy were included in the first series of observations. Computed tomography (CT) scans were assessed using the Lund-Mackay scores (LMS) before and 7.6 ± 3.0 months after starting the therapy. In addition, the changes in sweat chloride levels and pulmonary function test results were taken into account. The control group included 11 patients with comparable initial radiographic data who did not receive such therapy.Results and discussion. The treatment group showed a significant improvement in the PNS condition in the form of a decrease in the LMS scores from 15.6 ± 4.5 to 2.1 ± 3.0 (p = 0.001) with inhomogeneous changes vs different PNS groups. A certain parallelism between changes in the CT view and the level of sweat chlorides and pulmonary function test results was reported. In the control group, a nonsignificant deterioration in the course of CRS was observed (from 12.3 ± 6.3 to 14.6 ± 4.9 scores according to LMS; p = 0.108).Conclusions. The study demonstrated high efficacy of CF triple targeted therapy with ivacaftor/elexacaftor/tezacaftor in relation to the severe CRS with a rapid onset of effect in the form of PNS pneumatization restoration according to CT findings.

Biomimetic nanovesicle co-delivery system impairs energy metabolism for cancer treatment

Metabolic reprogramming in cancer cells plays a crucial role in cancer development, metastasis and invasion. Cancer cells have a unique metabolism profile that could switch between glycolysis and oxidative phosphorylation (OXPHOS) in order to satisfy a higher proliferative rate and enable survival in tumor microenvironment. Although dietary-based cancer starvation therapy has shown some positive outcomes for cancer treatment, it is difficult for patients to persist for a long time due to the adverse effects. Here in this study, we developed a specific M1 macrophage-derived membrane-based drug delivery system for breast cancer treatment. Both metformin and 3-Bromopyruvate were loaded into the engineered cell membrane-based biomimetic carriers (Met-3BP-Lip@M1) for the shutdown of energy metabolism in cancer cells via simultaneous inhibition of both glycolysis and oxygen consumption. The in vitro studies showed that Met-3BP-Lip@M1 had excellent cancer cell uptake and enhanced cancer cell apoptosis via cell cycle arrest. Our results also demonstrated that this novel biomimetic nanomedicine-based cancer starvation therapy synergistically improved the therapeutic efficiency against breast cancer cells by blocking energy metabolic pathways, which resulted in a significant reduction of cancer cell proliferation, 3D tumor spheroid growth as well as in vivo tumor growth.

The crosslink between the hyaluronic acid and drugs treated by reactive oxygen species produced in plasma based on the molecular dynamics simulation

Hyaluronic Acid (HA)-based pre-drugs can enable targeted drug delivery to cancer cells with CD44-high expressing, thus, it is essential to design an efficient, target specific drug delivery system based on HA. Plasma, as a simple and clean tool, has been widely used in the modification and crosslinking of biological materials in recent years. In this paper, we used the Reactive Molecular Dynamic (RMD) to explore the reaction between reactive oxygen species (ROS) in plasma and HA with drugs (PTX, SN-38, and DOX), in order to examine possible drug-coupled systems. The simulation results indicated the acetylamino groups in HA could be oxidized to unsaturated acyl groups, which offers the possibility of crosslinking. Three drugs also exposed the unsaturated atoms under the impact of ROS, which can cross-link directly to HA through CO and CN bonds, forming a drug coupling system with better release. This study revealed the exposure of active sites on HA and drugs by ROS impact in plasma, allowing us to study the crosslinking mechanism between HA and drugs at molecular level deeply, and also provided a new light for establishment of HA-based targeted drug delivery system.

Production and characterization of a camelid single domain anti-CD22 antibody conjugated to DM1.

Antibody drug conjugates (ADCs) with twelve FDA approved drugs, known as a novel category of anti-neoplastic treatment created to merge the monoclonal antibody specificity with cytotoxicity effect of chemotherapy. However, despite many undeniable advantages, ADCs face certain problems, including insufficient internalization after binding, complex structures and large size of full antibodies especially in targeting of solid tumors. Camelid single domain antibody fragments (Nanobody®) offer solutions to this challenge by providing nanoscale size, high solubility and excellent stability, recombinant expression in bacteria, in vivo enhanced tissue penetration, and conjugation advantages. Here, an anti-human CD22 Nanobody was expressed in E.coli cells and conjugated to Mertansine (DM1) as a cytotoxic payload. The anti-CD22 Nanobody was expressed and purified by Ni-NTA resin. DM1 conjugated anti-CD22 Nanobody was generated by conjugation of SMCC-DM1 to Nanobody lysine groups. The conjugates were characterized using SDS-PAGE and Capillary electrophoresis (CE-SDS), RP-HPLC, and MALDI-TOF mass spectrometry. Additionally, flow cytometry analysis and a competition ELISA were carried out for binding evaluation. Finally, cytotoxicity of conjugates on Raji and Jurkat cell lines was assessed. The drug-to-antibody ratio (DAR) of conjugates was calculated 2.04 using UV spectrometry. SDS-PAGE, CE-SDS, HPLC, and mass spectrometry confirmed conjugation of DM1 to the Nanobody. The obtained results showed the anti-CD22 Nanobody cytotoxicity was enhanced almost 80% by conjugation with DM1. The binding of conjugates was similar to the non-conjugated anti-CD22 Nanobody in flow cytometry experiments. Concludingly, this study successfully suggest that the DM1 conjugated anti-CD22 Nanobody can be used as a novel tumor specific drug delivery system.

Nanosponges: A Novel Class of Versatile Drug Delivery System – Review

Nanotechnology advancements have resulted in the creation of tailored medicine delivery systems. However, properly targeting a molecule to a specific region with a drug delivery system necessitates using a specialized drug delivery system. The development of nanosponge has become a crucial step in solving some challenges such as drug toxicity, low bioavailability, and predictable drug release. Many drug delivery methods, such as nanoparticles, nanoemulsions, nanosuspensions, and nanosponges, have been developed via nanomedicine technology. Nanosponges are little sponges like the size of a virus that may be loaded with a vast range of medications. Nanosponges serve an essential function in regulated medication delivery. These mini sponges may flow throughout the human body until they reach the same target region. They adhere to the surface and begin to release the medicine in a regulated and predictable way. The outside surface is often porous, which allows for regulated medication release. The important feature of these sponges is their aqueous solubility, which makes them appropriate for medications with low solubility. Their molecular architecture is often composed of several polymer chains that can generate unique microdomains suited for co-encapsulating two medicines with different chemical structures. When used to release insoluble medications, nanosponges also shield the active components from physicochemical deterioration. Nanosponges can be made into a number of dosage forms, including parenteral, aerosol, tablets, topical, and capsules, thanks to their small size and spherical structure. This study focuses on the techniques of synthesis and applications of nanosponges in the realm of medication delivery.

Monoclonal Antibodies as a Site Specific Particulate Drug Delivery System: A Review

Monoclonal antibodies are antibodies that are identical because they were produced by one type of immune cell, all Human monoclonal antibody immunotherapy in clinical medicine has been an exciting prospect for some time, and increasing numbers of such antibodies have gradually become available. Targets and basic characterization of novel classes of bioactive agents, to the development of ‘designer’ or ‘smart’ materials which provide required excipient or carrier properties to achieve modulated and targeted drug delivery. Drug particle engineering, or crystal engineering, provides an additional dimension to drug delivery and targeting. Traditional methods of particle formation, crystallization. Antibodies can be heterogeneous with respect to size, charge, antigen specificity, and affinity. These factors may be significant when antibodies are used as a drug delivery system. Drug targeting and delivery using antibodies has been most useful in the field of chemotherapy because this is an area of research in which there is the greatest need for target-site specificity. Antibodies have been found to have many applications in the management of human carcinomas, including colorectal, gastric, ovarian, endometrial, breast, lung.

Formulation and Evaluation of Sustained Release Solid Dispersed Nifedipine Microcapsules

Conventional drug delivery system for treating the angina and hypertension are not much effective as the drug do not reach the site of action in appropriate amounts. Thus potent and guarded therapy of this angina and hypertension disorder using specific drug delivery system is a challenging task to the pharmaceutical professionals. The study was aimed at increase the solubility of poorly soluble drug nifedipine and formulating it in sustained release dosage form. Solid dispersion of drug was prepared using Poly vinyl pyrrolidone (PVP) as inert hydrophilic carriers by solvent evaporation technique. A 17-fold increase in dissolution rate of nifedipine was observed with solid dispersion prepared with PVP (K30). Sustained release microcapsules of nifedipine were formulated using Eudragit RS 100 as a polymer, acetone as polymer solvent for Eudragit RS100, N-hexane as a non-solvent, liquid paraffin vehicle, with solid dispersion of nifedipine as core by emulsion solvent evaporation method and modified emulsion solvent evaporation method. Microcapsules from all the batches were found to discrete, spherical and free flowing and % entrapment efficiency was found to be in range of 96.01% to 97.87%. All the batches of microcapsules showed sustained release curve in pH 7.4 phosphate buffer up to 12hours with maximum release up to 97.22% after 12hrs was found to be in B2. SEM studies of the microcapsules showed the surface topography states that prepared microspheres were spherical in shape. Shiny and uniform covered surface with polymer. Keywords: Nifedipine, Poly vinyl pyrrolidone, Solid dispersion, Microcapsules, Emulsion solvent evaporation method

Determination of 3D structure and molecular interaction for mir-135b and its silencer as Triple Negative Breast Cancer (TNBC) biomarkers

Triple Negative Breast Cancer (TNBC) is considered as the most dangerous breast cancer type in women and the most difficult to be medicated due to its unresponsive nature towards drug treatments. However, as transcriptomics studies are becoming more advanced, the research on non-coding (nc)RNAs like miRNA and siRNA is being considered as a more feasible approach to deal with TNBC. The mir-135b, a newly found miRNA that has a role in the molecular mechanism of TNBC, is studied mainly for its function as a possible biomarker and a drug candidate. The molecular interaction and structures are still unknown and determining them is the objective of this research. This research utilizes the RNAComposer webservice for 3D RNA structure prediction and the AutoDockTool for molecular docking to determine their interaction. The result shows satisfactory illustration of mir-135b and its siRNA structures with feasible bindings between them. It is shown that the bindings are strong enough to maintain silencing of the gene. However, the molecular docking result shows reversible interaction based on the binding energy meaning its biomarker potential requires combination with other special drug delivery systems. It could be inferred that the siRNAs have potential to be developed in the wet laboratory settings.

NATURAL BIODEGRADABLE CIPROFLOXACIN MICROSPHERES: OPTIMIZATION STUDY BY FACTORIAL DESIGN

Oral drug delivery is the most popular method of control and release of therapeutic agents for the management of diseases. The colon specific drug delivery systems are considered to attain targeted drug delivery to the large intestine specifically at colon. They provide local delivery for the treatment of colonic diseases like inflammatory bowel disease. The present investigation is based on response of percent drug release as dependent variable for the study at Y axis with two different variables-concentration of surfactant (X1) and stirring speed (X2). A 32 full factorial design was used for complete reading of blending of polymers. The effects of surfactant concentration and stirring speed were evaluated by different parameters as entrapment efficiency, particle size, surface characteristics, micromeritic properties, DSC study and in vitro drug release studies. The present investigation reveals that galactomannan gum containing microspheres are promising as a carrier for colon targeted delivery of ciprofloxacin.

Targeting Agents Used in Specific Bone-Targeting Drug Delivery Systems: A Review

Bone-targeting agent–based specific drug delivery has attracted increasing attention in current research involving bone-related diseases because of its ability to effectively reduce the administered dose of drugs and subsequent systemic toxicity. Bone-targeting agents determine the targeting characteristics of the drug delivery system and are the key components of the system. In this review, we summarize the most commonly used bone-targeting agents for bone drug delivery, including bisphosphonates, tetracyclines, peptides, and aptamers. We discuss the mechanisms by which these moieties bind to the bone matrix and specific bone cells and analyze the advantages and disadvantages of various targeting agents, such as the inflexible drug release time of small molecules and the poor biological stability of peptide agents. Furthermore, we introduce current specific bone-targeting drug delivery systems that utilize bone-targeting agents to provide a reference for the prospect and development of these delivery systems.

Experimental and theoretical investigation on the adsorption properties of benzene on graphene surface: Influence of pH and edge effects

Graphene materials, as drug carriers, play an important role in the specific drug delivery system. The drug molecules with aromatic structures can be adsorbed on the surface of graphene in vitro through π-π stacking interaction and released directionally at the lesion under special temperature and pH-value environment. This paper proposes a new experimental method and theoretical model for the purpose to study the effect and mechanism of environmental pH and edge of graphene on the adsorption mechanical properties between graphene and benzene. The experimental results based on atomic force microscope show that the acidic environment is more conducive to the adsorption of benzene on the surface of graphene than the alkaline environment. The adsorption performance of benzene at the center of graphene is better than that at the edge. Moreover, based on experimental results, mechanisms of pH effect and edge effect are revealed by potential function theory. The pH effect is influenced by the change of electrostatic interaction in different pH environments. In addition, edge effect is mainly dominated by van der Waals interaction. This study solves the problem of specific influence mechanism of pH on π-π stacking interaction using mechanical means for the first time, and shows that graphene as a drug carrier has strong pH response characteristics and great application potential.

Smart nanofibres for specific and ultrasensitive nanobiosensors and drug delivery systems

Biosensors are dynamically developing analytical devices for the detection of substrates or other bioactive substances. They can be used for quick gas or liquid analyses and the construction of sensitive detection systems. This review highlights the advances and development of biosensors suitable for human and veterinary medicine and, namely, a novel contribution of nanotechnology for ultrasensitive diagnosis and personalized medicine. The synergic effect of nanotechnology and biosensors opens a new dimension for effective treatment and disease detection at their early stages.