Tailor-made electrically-responsive poly(acrylamide)-graft-pullulan copolymer based transdermal drug delivery systems: Synthesis, characterization, in-vitro and ex-vivo evaluation

Evaluation of 3D-Printed Solid Microneedles Coated with Electrosprayed Polymeric Nanoparticles for Simultaneous Delivery of Rivastigmine and N-Acetyl Cysteine

In the current study, coated microneedle arrays were fabricated by means of digital light processing (DLP) printing. Three different shapes were designed, printed, and coated with PLGA particles containing two different actives. Rivastigmine (RIV) and N-acetyl-cysteine (NAC) were coformulated via electrohydrodynamic atomization (EHDA), and they were incorporated into the PLGA particles. The two actives are administered as a combined therapy for Alzheimer's disease. The printed arrays were evaluated regarding their ability to penetrate skin and their mechanical properties. Optical microscopy and scanning electron microscopy (SEM) were employed to further characterize the microneedle structure. Confocal laser microscopy studies were conducted to construct 3D imaging of the coating and to simulate the diffusion of the particles through artificial skin samples. Permeation studies were performed to investigate the transport of the drugs across human skin ex vivo. Subsequently, a series of tape strippings were performed in an attempt to examine the deposition of the APIs on and within the skin. Light microscopy and histological studies revealed no drastic effects on the membrane integrity of the stratum corneum. Finally, the cytocompatibility of the microneedles and their precursors was evaluated by measuring cell viability (MTT assay and live/dead staining) and membrane damages followed by LDH release.

Super-Macroporous Pulluan Cryogels as Controlled Active Delivery Systems with Controlled Degradability

Here, super-macroporous cryogel from a natural polysaccharide, pullulan was synthesized using a cryo-crosslinking technique with divinyl sulfone (DVS) as a crosslinker. The hydrolytic degradation of the pullulan cryogel in various simulated body fluids (pH 1.0, 7.4, and 9.0 buffer solutions) was evaluated. It was observed that the pullulan cryogel degradation was much faster in the pH 9 buffer solution than the pH 1.0 and 7.4 buffer solutions in the same time period. The weight loss of the pullulan cryogel at pH 9.0 within 28 days was determined as 31% ± 2%. To demonstrate the controllable drug delivery potential of pullulan cryogels via degradation, an antibiotic, ciprofloxacin, was loaded into pullulan cryogels (pullulan-cipro), and the loading amount of drug was calculated as 105.40 ± 2.6 µg/mg. The release of ciprofloxacin from the pullulan-cipro cryogel was investigated in vitro at 37.5 °C in physiological conditions (pH 7.4). The amount of drug released within 24 h was determined as 39.26 ± 3.78 µg/mg, which is equal to 41.38% ± 3.58% of the loaded drug. Only 0.1 mg of pullulan-cipro cryogel was found to inhibit half of the growing Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) colonies for 10 min and totally eradicated within 2 h by the release of the loaded antibiotic. No significant toxicity was determined on L929 fibroblast cells for 0.1 mg drug-loaded pullulan cryogel. In contrast, even 1 mg of drug-loaded pullulan cryogel revealed slight toxicity (e.g., 66% ± 9% cell viability) because of the high concentration of released drug.

Recent Development of Nanomaterials for Transdermal Drug Delivery

Nano-engineered medical products first appeared in the last decade. The current research in this area focuses on developing safe drugs with minimal adverse effects associated with the pharmacologically active cargo. Transdermal drug delivery, an alternative to oral administration, offers patient convenience, avoids first-pass hepatic metabolism, provides local targeting, and reduces effective drug toxicities. Nanomaterials provide alternatives to conventional transdermal drug delivery including patches, gels, sprays, and lotions, but it is crucial to understand the transport mechanisms involved. This article reviews the recent research trends in transdermal drug delivery and emphasizes the mechanisms and nano-formulations currently in vogue.

Fabricating gum polysaccharides based nano-composites for drug delivery uses via sustainable green approach

Recent advancements in development of natural polymer nono-composites led to exploration of potential of gum acacia (GA) and tragacanth gum (TG) for design of silver nanoparticles (AgNPs) impregnated grafted copolymers via green approach for use in drug delivery (DD). The formation of copolymers was confirmed by UV-Vis spectroscopy, TEM, SEM, AFM, XPS, XRD, FTIR,TGA and DSC. UV-Vis spectra indicated the formation of AgNPs using GA as reducing agent. TEM, SEM, XPS and XRD revealed impregnation of AgNPs inside the copolymeric network hydrogels. TGA inferred thermal stability of polymer enhanced by grafting and incorporation of AgNPs. The non-Fickian diffusion of antibiotic drug meropenem was revealed from drug encapsulated GA-TG-(AgNPs)-cl-poly(AAm) network which were also pH responsive and release profile was fitted in Korsmeyer-Peppas kinetic model. Sustained release was due to polymer-drug interaction. The polymer-blood interaction demonstrated biocompatible characteristics of polymer. Mucoadhesive property exhibited by copolymers because of supra-molecular interactions. Antimicrobial characteristics were shown by copolymers against bacteria S. flexneri, P. auroginosa, and B. cereus.

The advance anticancer role of polymeric core-shell ZnO nanoparticles containing oxaliplatin in colorectal cancer

We evaluated the activity of core-shell ZnO nanoparticles (ZnO-NPs@polymer shell) containing Oxaliplatin via polymerization through in vitro studies and in vivo mouse models of colorectal cancer. ZnO NPs were synthesized in situ when the polymerization step was completed by co-precipitation. Gadolinium coordinated-ZnONPs@polymer shell (ZnO-Gd NPs@polymer shell) was synthesized by exploiting Gd's oxophilicity (III). The biophysical properties of the NPs were studied using powder X-ray diffraction (PXRD), Fourier transforms infrared spectroscopy, Ultraviolet-visible spectroscopy (UV-Vis), field emission electron microscopy (FESEM), transmission electron microscopy (TEM), atomic force microscopy, dynamic light scattering, and z-potential. (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) was used to determine the antiproliferative activity of ZnO-Gd-OXA. Moreover, a xenograft mouse model of colon cancer was exerted to survey its antitumor activity and effect on tumor growth. In the following, the model was also evaluated by histological staining (H-E; Hematoxylin & Eosin and trichrome staining) and gene expression analyses through the application of RT-PCR/ELISA, which included biochemical evaluation (MDA, thiols, SOD, CAT). The formation of ZnO NPs, which contained a crystallite size of 16.8 nm, was confirmed by the outcomes of the PXRD analysis. The Plate-like morphology and presence of Pt were obtained in EDX outcomes. TEM analysis displayed the attained ZnO NPs in a spherical shape and a diameter of 33 ± 8.5 nm, while the hydrodynamic sizes indicated that the particles were highly aggregated. The biological results demonstrated that ZnO-Gd-OXA inhibited tumor growth by inducing reactive oxygen species and inhibiting fibrosis, warranting further research on this novel colorectal cancer treatment agent.

CuZn Complex Used in Electrical Biosensors for Drug Delivery Systems

This paper is to discuss the potential of using CuZn in an electrical biosensor drug carrier for drug delivery systems. CuZn is the main semiconductor ingredient that has great promise as an electrochemical detector to trigger releases of active pharmaceutical ingredients (API). This CuZn biosensor is produced with a green metal of frameworks, which is an anion node in conductive polymers linked by bioactive ligands using metal-polymerisation technology. The studies of Cu, Zn, and their oxides are highlighted by their electrochemical performance as electrical biosensors to electrically trigger API. The three main problems, which are glucose oxidisation, binding affinity, and toxicity, are highlighted, and their solutions are given. Moreover, their biocompatibilities, therapeutic efficacies, and drug delivery efficiencies are discussed with details given. Our three previous investigations of CuZn found results similar to those of other authors' in terms of multiphases, polymerisation, and structure. This affirms that our research is on the right track, especially that related to green synthesis using plant extract, CuZn as a nanochip electric biosensor, and bioactive ligands to bind API, which are limited to the innermost circle of the non-enzymatic glucose sensor category.

Composing On-Program Triggers and On-Demand Stimuli into Biosensor Drug Carriers in Drug Delivery Systems for Programmable Arthritis Therapy

Medication in arthritis therapies is complex because the inflammatory progression of rheumatoid arthritis (RA) and osteoarthritis (OA) is intertwined and influenced by one another. To address this problem, drug delivery systems (DDS) are composed of four independent exogenous triggers and four dependent endogenous stimuli that are controlled on program and induced on demand, respectively. However, the relationships between the mechanisms of endogenous stimuli and exogenous triggers with pathological alterations remain unclear, which results in a major obstacle in terms of clinical translation. Thus, the rationale for designing a guidance system for these mechanisms via their key irritant biosensors is in high demand. Many approaches have been applied, although successful clinical translations are still rare. Through this review, the status quo in historical development is highlighted in order to discuss the unsolved clinical difficulties such as infiltration, efficacy, drug clearance, and target localisation. Herein, we summarise and discuss the rational compositions of exogenous triggers and endogenous stimuli for programmable therapy. This advanced active pharmaceutical ingredient (API) implanted dose allows for several releases by remote controls for endogenous stimuli during lesion infections. This solves the multiple implantation and local toxic accumulation problems by using these flexible desired releases at the specified sites for arthritis therapies.

In Vitro and In Vivo Biocompatible and Controlled Resveratrol Release Performances of HEMA/Alginate and HEMA/Gelatin IPN Hydrogel Scaffolds

Scaffold hydrogel biomaterials designed to have advantageous biofunctional properties, which can be applied for controlled bioactive agent release, represent an important concept in biomedical tissue engineering. Our goal was to create scaffolding materials that mimic living tissue for biomedical utilization. In this study, two novel series of interpenetrating hydrogel networks (IPNs) based on 2-hydroxyethyl methacrylate/gelatin and 2-hydroxyethyl methacrylate/alginate were crosslinked using N-ethyl-N'-(3-dimethyl aminopropyl)carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). Characterization included examining the effects of crosslinker type and concentration on structure, morphological and mechanical properties, in vitro swelling, hydrophilicity as well as on the in vitro cell viability (fibroblast cells) and in vivo (Caenorhabditis elegans) interactions of novel biomaterials. The engineered IPN hydrogel scaffolds show an interconnected pore morphology and porosity range of 62.36 to 85.20%, favorable in vitro swelling capacity, full hydrophilicity, and Young's modulus values in the range of 1.40 to 7.50 MPa. In vitro assay on healthy human fibroblast (MRC5 cells) by MTT test and in vivo (Caenorhabditis elegans) survival assays show the advantageous biocompatible properties of novel IPN hydrogel scaffolds. Furthermore, in vitro controlled release study of the therapeutic agent resveratrol showed that these novel scaffolding systems are suitable controlled release platforms. The results revealed that the use of EDC and the combination of EDC/NHS crosslinkers can be applied to prepare and tune the properties of the IPN 2-hydroxyethyl methacrylate/alginate and 2-hydroxyethyl methacrylate/gelatin hydrogel scaffolds series, which have shown great potential for biomedical engineering applications.

A stretchable and healable elastomer with shape memory capability based on multiple hydrogen bonds

Although a wide range of self-healing materials have been reported by researchers, it is still a challenge to endow exceptional mechanical properties and shape memory characteristics simultaneously in a single material. Inspired by the structure of natural silk, herein, we have adopted a simple synthetic method to prepare a kind of elastomer (HM-PUs) with stiff, healable and shape memory capabilities assisted by multiple hydrogen bonds. The self-healing elastomer exhibits a maximum tensile strength of 39 MPa, toughness of 111.65 MJ m⁻³ and self-healing efficiency of 96%. Moreover, the recuperative efficiency of shape memory could reach 100%. The fundamental study of HM-PUs will facilitate the development of flexible electronics and medical materials.

Although a wide range of self-healing materials have been reported by researchers, it is still a challenge to endow exceptional mechanical properties and shape memory characteristics simultaneously in a single material.

Hyaluronic acid-coated chitosan nanoparticles as targeted-carrier of tamoxifen against MCF7 and TMX-resistant MCF7 cells

Tamoxifen (TMX) is used to treat hormone-receptor-positive breast cancers at early stages. This research aimed to assess the potential of NPs in targeted delivery of TMX against MCF7 and TMX-resistant MCF7 breast cancer cell lines. For this purpose, a targeted delivery system including chitosan NPs coated with hyaluronic acid (HA-CS NPs) was created and examined in vitro. Chitosan NPs were first fabricated and loaded with TMX using the ionic-gelation method to prepare a drug-delivery system. Then, TMX-loaded CS NPs were coated by crosslinking the amino groups of chitosan to the carboxylic group of hyaluronic acid. The developed TMX delivery system was then optimized and characterized for particle fabrication, drug release, and targeting against cancer cells. The HA-CS particle size was 210 nm and its zeta potential was +25 mv. The encapsulation efficiency of TMX in NPs was 55%. TMX released from the NPs in acidic pH (5-6) was higher than the physiological pH (7.4). The cytotoxic effect of TMX-loaded HA-CS NPs on MCF7 and TMX-resistant MCF7 cells was significantly higher than TMX-loaded CS NPs and free drug. The findings confirmed the significant suppressive impact of TMX-loaded HA-CS NPs on MCF7 and TMX-resistant MCF7 cancer cells compared to the TMX-loaded CS NPs and free TMX. Graphical abstract.

Novel polymeric hydrogel composites: Synthesis, physicochemical, mechanical and biocompatible properties

In this research study, novel hydrogel composite films were constructed using different ratios of poly (vinyl alcohol) (PVA)/kappa-carrageenan (KC) (PVA90/KC10%, PVA80/KC20%, PVA70/KC30%, PVA60/KC40%) crosslinked with glutaraldehyde (0.025%) and investigated their physicochemical characteristics such as mechanical, thermal, morphological, swelling behaviour, and cell viability. SEM and FTIR revealed that surface morphology changed to heterogeneous and the presence of molecular interaction among the polymers. PVA90KC10 and PVA60KC40 exhibited smaller and larger pores on surface respectively. The change in the proportion of PVA and KC also triggered the tensile strength (Ts) of the film and the highest Ts observed were 21.60 MPa for PVA60KC40. Moreover, the thermal analysis showed three-phase degradation, and an increase in KC40 concentration results inversely proportional to a decrease in the rate of thermal degradation. Further, swelling and in-vitro biodegradation study confirmed the enhanced perseverance of water uptake for PVA60KC40 (286%) due to pores structure of the hydrogel film and PVA and KC alone degraded faster as compare to other films results suggested higher concentration of PVA90KC10 showed lower degradation rate and highest for PVA60KC40 about 6% and 22% respectively. Further, the cell viability was studied with MTT assay method by using NIH3T3 and HEK-293 cells for biocompatibility study revealed NIH3T3 cells were more biocompatible than HEK-293 and cell viability percent for PVA60KC40 showed the highest cell attachment about 99%. Overall corroborating data obtained from the study attested to the average swelling, appreciable mechanical characters, good interaction between molecules, and cell viability of the constructed PVA/KC hydrogel film, these all characters pave to be used as a potential template for biomedical applications such as tissue engineering and drug delivery.

Chitosan functionalized graphene oxide nanocomposites for fluorescence imaging of apoptotic processes and targeted anti-inflammation study

This work reports novel chitosan functionalized graphene oxide (GO) nanocomposites combined fluorescence imaging and therapeutic functions in one agent, which can serve as a promising alternative to alleviate related diseases caused hyperinflammation. Briefly, GO was designed to be conjugated with chitosan, fluorescein-labeled peptide, toll-like receptor 4 antibody and hydroxycamptothecin/aloe emodin. We have demonstrated that such nanocomposites could effectively achieve active targeted delivery of pro-apoptotic and anti-inflammatory drugs into inflammatory cells and cause cells apoptosis by acid-responsive drug release. Moreover, confocal fluorescence imaging confirms that the drug-induced inflammatory cells apoptosis could be visualized the light-up fluorescence of fluorescein activated by caspase-3. Meanwhile, inflammatory-related biomarkers have down-regulated after the nanocomposites' treatment in both vitro and vivo experiments consistent with the results in histological sections. In summary, the bifunctional nanocomposites that possess anti-inflammation and fluorescence imaging could serve as a promising therapeutic agent for reducing hyperinflammation caused by numerous diseases.

Microfibrillated cellulose films containing chitosan and tannic acid for wound healing applications

The effectiveness of tannic acid as antimicrobial and wound healing for burns have been shown for a century; however, uncontrolled target dosage may result in undesirable side-effects. Remarkably, tannic acid polyphenols compounds crosslinked with polymeric materials produce a strong composite containing the beneficial properties of this tannin. However, investigation of the crosslink structure and its antibacterial and regenerative properties are still unknown when using nanocellulose by mechanical defibrillation; additionally, due to the potential crosslink structure with chitosan, its structure can be complex. Therefore, this work uses bleach kraft nanocellulose in order to investigate the effect on the physical and regenerative properties when incorporated with chitosan and tannic acid. This film results in increased rigidity with a lamellar structure when incorporated with tannic acid due to its strong hydrogen bonding. The release of tannic acid varied depending on the structure it was synthesised with, whereas with chitosan it presented good release model compared to pure cellulose. In addition, exhibiting similar thermal stability as pure cellulose films with antibacterial properties tested against S. aureus and E. coli with good metabolic cellular viability while also inhibiting NF-κB activity, a characteristic of tannic acid.

Tailoring of P-glycoprotein for effective transportation of actives across blood-brain-barrier

P-Glycoprotein serves as a gatekeeper in the blood-brain-barrier wherein, it shows a vital part in the elimination of xenobiotics, drugs, foreign molecules etc. and guards the central nervous system from infections and external toxic molecules by functioning as an efflux transporter. It plays an essential role in various brain-related conditions like Parkinsonism, Alzheimer's disease, depression, cancer, etc. and terminates the entry of therapeutic agents across blood-brain-barrier which remains a significant challenge serving as major hindrance in pharmacotherapy of disease. The physiological structure and topology of P-glycoprotein and its relation with blood-brain-barrier and central nervous system gives an idea for targeting nanocarriers across the barrier into brain. This review article provides an overview of current understanding of the nanoformulations-based P-gp trafficking strategies like nanocarriers, stem cell therapy, drugs, substrates, polymeric materials, chemical compounds as well as naturally occurring active constituents for improving drug transport in brain across blood-brain-barrier and contributing in effective nanotherapeutic development for treatment of CNS disorders.

Development and physicochemical characterization of novel porous phosphate glass bone graft substitute and in vitro comparison with xenograft

The process of bone regeneration in bone grafting procedures is greatly influenced by the physicochemical properties of the bone graft substitute. In this study, porous phosphate glass (PPG) morsels were developed and their physicochemical properties such as degradation, crystallinity, organic content, surface topography, particle size and porosity were evaluated using various analytical methods. The in vitro cytotoxicity of the PPG morsels was assessed and the interaction of the PPG morsels with Dental Pulp Stem Cells (DPSCs) was studied by measuring cell proliferation and cell penetration depth. The cell-material interactions between PPG morsels and a commercially available xenograft (XG) were compared. The PPG morsels were observed to be amorphous, biocompatible and highly porous (porosity = 58.45%). From in vitro experiments, PPG morsels were observed to be non-cytotoxic and showed better cell proliferation. The internal surface of PPG was easily accessible to the cells compared to XG.

Construction and performance evaluation of a sustained release implant material polyetheretherketone with antibacterial properties

OBJECTIVE

This study aimed to construct a tightly binding antibiotic sustained release system on the polyetheretherketone (PEEK) surface and investigate the cellular activity and antibacterial properties of the new oral implant materials.

METHODS

Low-temperature argon plasma under certain parameters was used to prepare P-PEEK with nano-topology, and chemical deposition technology was adopted to form a polydopamine (PDA) coating on the PEEK surface to build a biological binding platform, PDA/P-PEEK. Subsequently, vancomycin gelatin nanoparticles (Van-GNPs) were prepared by two-step desolvation method. Finally, Van-GNPs were combined with PEEK implant material surface to form a new composite material, Van-GNPs/PEEK. scanning electron microscope (SEM), atomic force microscope (AFM), energy dispersive spectrometer (EDS), and contact angle tester were used to comprehensively characterize the materials. The in vitro release test of Van was performed by dynamic dialysis with ultraviolet spectrophotometer. The cell cytotoxicity and adhesion tests were studied by mouse embryonic osteoblasts. The antibacterial properties were evaluated by bacterial adhesion test, plate colony counting, and antimicrobial ring test with Staphylococcus aureus and Streptococcus mutans.

RESULTS

PEEK was treated with low-temperature argon plasma and attached to PDA to form a biological binding platform. The synthesized Van-GNPs were smooth, round, with uniform particle size distribution, and bound to PEEK to form a new composite material, which can release Van constantly. Cell experiments showed that Van-GNPs/PEEK had no cytotoxicity and had good interaction with osteoblasts. Bacterial experiments showed that surface conjugation with Van-GNPs could significantly improve the antibacterial performance of PEEK against S. aureus and S. mutans.

SIGNIFICANCE

This study demonstrated that Van-GNPs/PEEK have good cellular compatibility and autonomous antibacterial properties, which provide a theoretical basis for the wide application of PEEK in the field of stomatology.

Oral administration co-delivery nanoparticles of docetaxel and bevacizumab for improving intestinal absorption and enhancing anticancer activity

In this study, to improve the intestinal absorption of small molecule chemotherapeutic drug docetaxel (DTX) and macromolecular monoclonal antibody drug bevacizumab (BVZ), we designed and prepared a type of co-delivery nanoparticles for the oral administration of DTX and BVZ. Carboxymethyl chitosan (CMC) and poly(lactic-co-glycolic acid) (PLGA) were used as the carrier of DTX nanoparticles (CPNP_DTX), and methoxy polyethylene glycol-poly (β-amino ester) (mPEG-PAE) was used as the carrier of BVZ nanoparticles (PPNP_BVZ). Then, the two nanoparticles were physically mixed in mass ratios to form mixed co-delivery nanoparticles, which was named as CPNP_DTX&PPNP_BVZ. The nanoparticles were characterized with pH-sensitive drug release property. CPNP_DTX&PPNP_BVZ could significantly increase the bioavailability of DTX and BVZ according to the more cellular uptake in Caco-2 cells and the higher absorption in the intestinal tissue. Compared with free DTX and BVZ, CPNP_DTX&PPNP_BVZ showed excellent cytotoxic effects on A549 cells. Our study revealed the potential of co-delivery nanoparticles of binary mixture of chemotherapeutic small molecule and macromolecular antibody drug as an oral administration therapeutic system.

Electrospun PVP/PVA Nanofiber Mat as a Novel Potential Transdermal Drug-Delivery System for Buprenorphine: A Solution Needed for Pain Management

Over the past several decades, the formulation of novel nanofiber-based drug-delivery systems has been a frequent focus of scientists around the world. Aiming to introduce a novel nanofibrous transdermal drug-delivery system to treat pain, the nanofiber mats of buprenorphine-loaded poly (vinyl pyrrolidone) (Bup/PVP) and buprenorphine-loaded poly(vinyl alcohol)/poly(vinyl pyrrolidone) (Bup/PVP/PVA) were successfully fabricated by the electrospinning process for transdermal drug delivery. Similarly, PVP and PVP/PVA nanofibers were fabricated in the same conditions for comparison. The viscosity and electrical conductivity of all electrospinning solutions were measured, and nanofiber mats were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FT-IR) spectroscopy and contact angle analysis. The conductivity of PVP and PVP/PVA solutions showed a considerable increase by the addition of buprenorphine due to the polarity of buprenorphine. SEM images showed a smooth, fine and porous nanofibrous structure without any adhesion or knot for all of the samples. The contact angle analysis showed the increased hydrophilicity and wettability of PVP/PVA and Bup/PVP/PVA nanofibers compared to PVP and Bup/PVP nanofibers which can be attributed to the addition of PVA. Attenuated total reflectance (ATR) FT-IR results confirmed that the electrospinning process did not affect the chemical integrity of the drug. For the modification of the drug release rate, the cross-linking of nanofiber mats was carried out using glutaraldehyde. Drug release measurements using high-performance liquid chromatography (HPLC) analysis demonstrated that Bup/PVP/PVA nanofibers exhibited better physical and chemical properties compared to Bup/PVP. Furthermore, the cross-linking of nanofibers led to an increase in drug release time. Thus, the novel buprenorphine-loaded nanofibers can be efficient biomaterial patches for transdermal delivery against pain improving carrier retention and providing a controlled release of the drug.

Engineered drug delivery devices to address Global Health challenges

There is a dire need for innovative solutions to address global health needs. Polymeric systems have been shown to provide substantial benefit to all sectors of healthcare, especially for their ability to extend and control drug delivery. Herein, we review polymeric drug delivery devices for vaccines, tuberculosis, and contraception.

Recent Advancements in Stimuli Responsive Drug Delivery Platforms for Active and Passive Cancer Targeting

The tumor-specific targeting of chemotherapeutic agents for specific necrosis of cancer cells without affecting the normal cells poses a great challenge for researchers and scientists. Though extensive research has been carried out to investigate chemotherapy-based targeted drug delivery, the identification of the most promising strategy capable of bypassing non-specific cytotoxicity is still a major concern. Recent advancements in the arena of onco-targeted therapies have enabled safe and effective tumor-specific localization through stimuli-responsive drug delivery systems. Owing to their promising characteristic features, stimuli-responsive drug delivery platforms have revolutionized the chemotherapy-based treatments with added benefits of enhanced bioavailability and selective cytotoxicity of cancer cells compared to the conventional modalities. The insensitivity of stimuli-responsive drug delivery platforms when exposed to normal cells prevents the release of cytotoxic drugs into the normal cells and therefore alleviates the off-target events associated with chemotherapy. Contrastingly, they showed amplified sensitivity and triggered release of chemotherapeutic payload when internalized into the tumor microenvironment causing maximum cytotoxic responses and the induction of cancer cell necrosis. This review focuses on the physical stimuli-responsive drug delivery systems and chemical stimuli-responsive drug delivery systems for triggered cancer chemotherapy through active and/or passive targeting. Moreover, the review also provided a brief insight into the molecular dynamic simulations associated with stimuli-based tumor targeting.

Optimization of propofol loaded niosomal gel for transdermal delivery

Propofol is an oily liquid widely used for rapid onset of anaesthesia via intravenous route, which shows major limitations of hypersensitivity, anaphylactic reactions and pain. The aim of the present work was to bypass the above issues by formulating tailored niosomal gel to deliver propofol via non-invasive transdermal route. The niosomes were prepared by film hydration method and sonication using cholesterol and Span 80. The Box Behnken design (BBD) was applied to optimize the size (93.5 nm) and the entrapment efficacy (81.5%) of the niosomes by selecting cholesterol at 139 mg, Span 80 at 0.525% and sonication time at 5.13 min. The scanning electron microscopy image showed spherical shape niosomes with smooth surface without aggregation. The ex vivo release data showed significant improvement in the propofol release (92.2% after 10 h) using niosomes in comparison to the control propofol gel (with 30% methanol) without niosomes (25.3% after 10 h). The in vivo pharmacokinetic parameters in the rat model confirmed the improvement in the relative bioavailability with optimized niosomal gel (relative bioavailability = 12.12) in comparison to the control propofol gel. In conclusion, the niosomal gel offered a potential alternative non-invasive route to deliver propofol for procedural sedation especially in pediatric population.

Drug delivery to optimize angiogenesis imbalance in keloid: A review

The wound healing process involves three continuous stages. Where, any imbalance can lead to the formation of unwanted keloids, hypertrophic scar, or tumors. Keloids are any unpleasant, non-compliant comorbidity affecting a major section of people around the globe who acquire it either genetically or by pathological means as a result of a skin injury. Angiogenesis is unavoidable in the healing process after an injury or disruption of skin to promote tissue regeneration. Uncontrolled angiogenesis during the healing process can initiate the unwanted response in the wound that facilitate keloid. Angiogenic therapy is adapted to accelerate healing after an injury. Else ways, there exists a risk of keloid formation due to excessive angiogenesis during the wound healing process. There are numerous strategies to treat keloid. Anti-angiogenic factors are provided to patients post-surgery to prevent the keloid formation; however, they come into the picture after the formation of keloid. The available strategies to treat keloids are steroidal injections, surgical excision of the keloid, radiotherapy, pressure therapy, the use of cryosurgery, and many more. The available treatments are not promising in reducing the recurrent rate of keloids as there are chances of high re-occurrences with similar/larger lesions on the removed keloid site. In this review, we are discussing the importance of controlled angiogenesis with the help of controlled drug delivery strategies enabling the wound healing process without the induction of keloid.

Pullulan based stimuli responsive and sub cellular targeted nanoplatforms for biomedical application: Synthesis, nanoformulations and toxicological perspective

With growing interest in polymers of natural origin, innumerable polysaccharides have gained attention for their biomedical application. Pullulan, one of the FDA approved nutraceuticals, possesses multiple unique properties which make them highly advantageous for biomedical applications. This present review encompasses the sources, production, properties and applications of pullulan. It highlights various pullulan based stimuli-responsive systems (temperature, pH, ultrasound, magnetic), subcellular targeted systems (mitochondria, Golgi apparatus/endoplasmic reticulum, lysosome, endosome), lipid-vesicular systems (solid-lipid nanoparticles, liposomes), polymeric nanofibres, micelles, inorganic (SPIONs, gold and silver nanoparticles), carbon-based nanoplatforms (carbon nanotubes, fullerenes, nanodiamonds) and quantum dots. This article also gives insight into different biomedical, therapeutic and diagnostic applications of pullulan viz., imaging, tumor targeting, stem cell therapy, gene therapy, vaccine delivery, cosmetic applications, protein delivery, tissue engineering, photodynamic therapy and chaperone-like activities. The review also includes the toxicological profile of pullulan which is helpful for the development of suitable delivery systems for clinical applications.

Zero-order drug delivery: State of the art and future prospects

Pharmaceutical drugs are an important part of the global healthcare system, with some estimates suggesting over 50% of the world's population takes at least one medication per day. Most drugs are delivered as immediate-release formulations that lead to a rapid increase in systemic drug concentration. Although these formulations have historically played an important role, they can be limited by poor patient compliance, adverse side effects, low bioavailability, or undesirable pharmacokinetics. Drug delivery systems featuring first-order release kinetics have been able to improve pharmacokinetics but are not ideal for drugs with short biological half-lives or small therapeutic windows. Zero-order drug delivery systems have the potential to overcome the issues facing immediate-release and first-order systems by releasing drug at a constant rate, thereby maintaining drug concentrations within the therapeutic window for an extended period of time. This release profile can be used to limit adverse side effects, reduce dosing frequency, and potentially improve patient compliance. This review covers strategies being employed to attain zero-order release or alter traditionally first-order release kinetics to achieve more consistent release before discussing opportunities for improving device performance based on emerging materials and fabrication methods.

Self-assembled drug loaded glycosyl-protein metal nanoconstruct: Detailed synthetic procedure and therapeutic effect in solid tumor treatment

Nanotechnology-based drug delivery research has largely focused on developing well efficient localized delivery therapeutic agents to overcome the limitations of non-specificity and toxicity of conventional chemotherapy. Herein, we constructed a nanoplatform based on a self-assembled polysaccharide-protein conjugate to deliver anti-tumor drug doxorubicin and gold nanoparticles (DOX@PST-BSA AuNPs) for cancer therapy. The self-assembled DOX@PST-BSA AuNPs exhibited higher stability and thermal properties which enable them for drug delivery via passive targeting. The fluorescent property of the drug contributes to the self-monitoring of NPs Biodistribution in vitro and in vivo. Furthermore, the NPs showed negligible cytotoxicity and tissue accumulation in normal cells in vivo. Importantly, the NPs could load the anti-tumor drug with high encapsulation efficiency and competently delivered into the tumor microenvironment thereby inhibit tumor growth significantly through apoptotic induction. Notably, DOX@PST-BSA AuNPs exhibits low systemic toxicity and very few side effects in vivo. Based on the explored features, these NPs could serve as a promising multifunctional drug delivery nanoplatform for cancer therapy.