New strategy for controlled release of drugs. Potential pinpoint targeting with multiresponsive tetraaniline diblock polymer vesicles: site-directed burst release with voltage

Electrically conductive carbon-based (bio)-nanomaterials for cardiac tissue engineering

A proper self-regenerating capability is lacking in human cardiac tissue which along with the alarming rate of deaths associated with cardiovascular disorders makes tissue engineering critical. Novel approaches are now being investigated in order to speedily overcome the challenges in this path. Tissue engineering has been revolutionized by the advent of nanomaterials, and later by the application of carbon-based nanomaterials because of their exceptional variable functionality, conductivity, and mechanical properties. Electrically conductive biomaterials used as cell bearers provide the tissue with an appropriate microenvironment for the specific seeded cells as substrates for the sake of protecting cells in biological media against attacking mechanisms. Nevertheless, their advantages and shortcoming in view of cellular behavior, toxicity, and targeted delivery depend on the tissue in which they are implanted or being used as a scaffold. This review seeks to address, summarize, classify, conceptualize, and discuss the use of carbon-based nanoparticles in cardiac tissue engineering emphasizing their conductivity. We considered electrical conductivity as a key affecting the regeneration of cells. Correspondingly, we reviewed conductive polymers used in tissue engineering and specifically in cardiac repair as key biomaterials with high efficiency. We comprehensively classified and discussed the advantages of using conductive biomaterials in cardiac tissue engineering. An overall review of the open literature on electroactive substrates including carbon-based biomaterials over the last decade was provided, tabulated, and thoroughly discussed. The most commonly used conductive substrates comprising graphene, graphene oxide, carbon nanotubes, and carbon nanofibers in cardiac repair were studied.

Recent Progress in Nanostructured Smart Drug Delivery Systems for Cancer Therapy: A Review

Traditional treatment approaches for cancer involve intravenous chemotherapy or other forms of drug delivery. These therapeutic measures suffer from several limitations such as nonspecific targeting, poor biodistribution, and buildup of drug resistances. However, significant technological advancements have been made in terms of superior modes of drug delivery over the last few decades. Technical capability in analyzing the molecular mechanisms of tumor biology, nanotechnology─particularly the development of biocompatible nanoparticles, surface modification techniques, microelectronics, and material sciences─has increased. As a result, a significant number of nanostructured carriers that can deliver drugs to specific cancerous sites with high efficiency have been developed. This particular maneuver that enables the introduction of a therapeutic nanostructured substance in the body by controlling the rate, time, and place is defined as the nanostructured drug delivery system (NDDS). Because of their versatility and ability to incorporate features such as specific targeting, water solubility, stability, biocompatibility, degradability, and ability to reverse drug resistance, they have attracted the interest of the scientific community, in general, and nanotechnologists as well as biomedical scientists. To keep pace with the rapid advancement of nanotechnology, specific technical aspects of the recent NDDSs and their prospects need to be reported coherently. To address these ongoing issues, this review article provides an overview of different NDDSs such as lipids, polymers, and inorganic nanoparticles. In addition, this review also reports the challenges of current NDDSs and points out the prospective research directions of these nanocarriers. From our focused review, we conclude that still now the most advanced and potent field of application for NDDSs is lipid-based, while other significantly potential fields include polymer-based and inorganic NDDSs. However, despite the promises, challenges remain in practical implementations of such NDDSs in terms of dosage and stability, and caution should be exercised regarding biocompatibility of materials. Considering these aspects objectively, this review on NDDSs will be particularly of interest for small-to-large scale industrial researchers and academicians with expertise in drug delivery, cancer research, and nanotechnology.

Infochemistry and the Future of Chemical Information Processing

Nowadays, information processing is based on semiconductor (e.g., silicon) devices. Unfortunately, the performance of such devices has natural limitations owing to the physics of semiconductors. Therefore, the problem of finding new strategies for storing and processing an ever-increasing amount of diverse data is very urgent. To solve this problem, scientists have found inspiration in nature, because living organisms have developed uniquely productive and efficient mechanisms for processing and storing information. We address several biological aspects of information and artificial models mimicking corresponding bioprocesses. For instance, we review the formation of synchronization patterns and the emergence of order out of chaos in model chemical systems. We also consider molecular logic and ion fluxes as information carriers. Finally, we consider recent progress in infochemistry, a new direction at the interface of chemistry, biology, and computer science, considering unconventional methods of information processing.

Legumain-induced intracerebrally crosslinked vesicles for suppressing efflux transport of Alzheimer's disease multi-drug nanosystem

Brain barrier is both a protective permeability hurdle and a limitation site where therapeutic agents are excluded to enter the target region. Designing drug vehicle to overcome this notorious barrier bottle is challenging. Herein, we construct a stimuli-responsive self-assembled nanovesicle that delivers water-soluble drugs to prevent the efflux transport of brain barriers by responding to the endogenously occurring signals in Alzheimer's disease (AD) brain microenvironment. Once stimuli-responsive vesicles are accumulated in intracerebrally, the intrinsically occurring legumain endopeptidase cleaves the Ac-Ala-Ala-Asn-Cys-Asp (AK) short peptide on the drug vesicles to expose the 1,2 thiol amino group to cyclize with the cyano groups on 2-cyano-6-aminobenzothiazole (CABT) of the chaperone vesicles, thus triggering the formation of cross-linked micrometre-scale vesicles. Such a structural alteration completely prevents further brain barriers efflux. The superior neuroprotective capacity of cross-linked vesicles is validated in senescence accelerated mouse prone 8 (SAMP8). This smart multi-drug delivery vesicle is promising to serve as a powerful system for AD treatment and can be adapted for the therapy of other central nervous system (CNS) disorders.

Pseudo target release behavior of simvastatin through pH-responsive polymer based on dynamic imine bonds: Promotes rapid proliferation of osteoblasts

In this article, a simvastatin loaded pentaerythritol tetra(3-mercaptopropionate)-allylurea-poly(ethylene glycol) (SIM-loaded PETMP-AU-PEG) polymer with excellent biocompatibility by means of in-situ loading method was synthesized. The presence of the imine bonds has given the polymer system an excellent response performance to weak acidic environment. Specifically, for the SIM-loaded polymer, the simvastatin cumulative release dose is only 2.2% in the first 2 h, and the first 32 h of the cumulative release dose is less than 10% in pH 7.4; However, in pH 6.0, the first 2 h of the cumulative release dose is 65.2%, and the first 32 h of the cumulative release dose is almost 100%. MC3T3-E1 osteoblast cell culture experiments show that the SIM-loaded polymer at pH 6.0 can accelerate the proliferation of osteoblasts significantly, which is expected to promote the rapid proliferation of bone cells in clinical applications and accelerate the healing of the lesion region.

Stimulus-responsive vesicular polymer nano-integrators for drug and gene delivery

Over the past two decades, nano-sized biosystems have increasingly been utilized to deliver various pharmaceutical agents to a specific region, organ or tissue for controllable precision therapy. Whether solid nanohydrogel, nanosphere, nanoparticle, nanosheet, micelles and lipoproteins, or "hollow" nanobubble, liposome, nanocapsule, and nanovesicle, all of them can exhibit outstanding loading and releasing capability as a drug vehicle - in particular polymeric nanovesicle, a microscopic hollow sphere that encloses a water core with a thin polymer membrane. Besides excellent stability, toughness and liposome-like compatibility, polymeric nanovesicles offer considerable scope for tailoring properties by changing their chemical structure, block lengths, stimulus-responsiveness and even conjugation with biomolecules. In this review, we summarize the latest advances in stimulus-responsive polymeric nanovesicles for biomedical applications. Different functionalized polymers are in development to construct more complex multiple responsive nanovesicles in delivery systems, medical imaging, biosensors and so on.

Electroactive Amphiphiles for Addressable Supramolecular Nanostructures

In this focus review we aim to highlight an exciting class of materials, electroactive amphiphiles (EAAs). This class of functional amphiphilic molecules has been the subject of sporadic investigations over the last few decades, but little attempt has been made to date to gather or organise these investigations into a logical fashion. Here we attempted to gather the most important contributions, provide a framework in which to discuss them, and, more importantly, point towards the areas where we believe these EAAs will contribute to solving wider scientific problems and open new opportunities. Our discussions cover materials based on low molecular weight ferrocenes, viologens and anilines, as well as examples of polymeric and supramolecular EAAs. With the advances of modern analytical techniques and new tools for modelling and understanding optoelectronic properties, we believe that this area of research is ready for further exploration and exploitation.

Dual electrical switching permeability of vesicles via redox-responsive self-assembly of amphiphilic block copolymers and polyoxometalates

Electro-responsive vesicles were demonstrated based on an amphiphilic block copolymer PEO114-b-P(DCH-Ru)n and an inorganic nanoparticle polyoxometalate H3PMo12O40 (PMo12) via electrostatic interactions. After undergoing electrochemical reactions, vesicle membranes allow the migration of electrolyte ions and release of loaded cargos.

Oligoaniline-based conductive biomaterials for tissue engineering

The science and engineering of biomaterials have improved the human life expectancy. Tissue engineering is one of the nascent strategies with an aim to fulfill this target. Tissue engineering scaffolds are one of the most significant aspects of the recent tissue repair strategies; hence, it is imperative to design biomimetic substrates with suitable features. Conductive substrates can ameliorate the cellular activity through enhancement of cellular signaling. Biocompatible polymers with conductivity can mimic the cells' niche in an appropriate manner. Bioconductive polymers based on aniline oligomers can potentially actualize this purpose because of their unique and tailoring properties. The aniline oligomers can be positioned within the molecular structure of other polymers, thus painter acting with the side groups of the main polymer or acting as a comonomer in their backbone. The conductivity of oligoaniline-based conductive biomaterials can be tailored to mimic the electrical and mechanical properties of targeted tissues/organs. These bioconductive substrates can be designed with high mechanical strength for hard tissues such as the bone and with high elasticity to be used for the cardiac tissue or can be synthesized in the form of injectable hydrogels, particles, and nanofibers for noninvasive implantation; these structures can be used for applications such as drug/gene delivery and extracellular biomimetic structures. It is expected that with progress in the fields of biomaterials and tissue engineering, more innovative constructs will be proposed in the near future. This review discusses the recent advancements in the use of oligoaniline-based conductive biomaterials for tissue engineering and regenerative medicine applications.

STATEMENT OF SIGNIFICANCE

The tissue engineering applications of aniline oligomers and their derivatives have recently attracted an increasing interest due to their electroactive and biodegradable properties. However, no reports have systematically reviewed the critical role of oligoaniline-based conductive biomaterials in tissue engineering. Research on aniline oligomers is growing today opening new scenarios that expand the potential of these biomaterials from "traditional" treatments to a new era of tissue engineering. The conductivity of this class of biomaterials can be tailored similar to that of tissues/organs. To the best of our knowledge, this is the first review article in which such issue is systematically reviewed and critically discussed in the light of the existing literature. Undoubtedly, investigations on the use of oligoaniline-based conductive biomaterials in tissue engineering need further advancement and a lot of critical questions are yet to be answered. In this review, we introduce the salient features, the hurdles that must be overcome, the hopes, and practical constraints for further development.

An addressable packing parameter approach for reversibly tuning the assembly of oligo(aniline)-based supra-amphiphiles

An addressable packing parameter approach was developed for reversibly tuning the self-assembly of oligo(aniline)-based supra-amphiphiles.

We present a newly developed approach to non-covalently address the packing parameter of an electroactive amphiphile. The pH-responsive reversible switching of a tetra(aniline)-based cationic amphiphile, TANI-pentyl trimethylammonium bromide (TANI-PTAB), between self-assembled vesicles and nanowires by acid/base chemistry in aqueous solution is used to exemplify this approach. Trifluoroacetic acid (TFA) was selected as a prototypical acid to form emeraldine salt (ES) state (TANI(TFA)₂-PTAB) vesicles for this new class of small-molecule supramolecular amphiphiles. UV-vis-NIR spectroscopy, transmission electron microscopy (TEM), tapping-mode atomic force microscopy (AFM), and fluorescence spectroscopy were used to investigate the reversible structural transformation from vesicles to nanowires. We show that utilising different protonic acid-dopants for TANI-PTAB can regulate the packing parameter, and thus the final self-assembled structures, in a predictable fashion. We envisage potential application of this concept as smart and switchable delivery systems.

Cargo Release from Polymeric Vesicles under Shear

In this paper we study the release of cargo from polymeric nano-carriers under shear. Vesicles formed by two star block polymers- A 12 B 6 C 2 ( A B C ) and A 12 B 6 A 2 ( A B A )-and one linear block copolymer- A 14 B 6 ( A B ), are investigated using dissipative particle dynamics (DPD) simulations. A - and C -blocks are solvophobic and B -block is solvophilic. The three polymers form vesicles of different structures. The vesicles are subjected to shear both in bulk and between solvophobic walls. In bulk shear, the mechanisms of cargo release are similar for all vesicles, with cargo travelling through vesicle membrane with no preferential release location. When sheared between walls, high cargo release rate is only observed with A B C vesicle after it touches the wall. For A B C vesicle, the critical condition for high cargo release rate is the formation of wall-polymersome interface after which the effect of shear rate in promoting cargo release is secondary. High release rate is achieved by the formation of solvophilic pathway allowing cargo to travel from the vesicle cavity to the vesicle exterior. The results in this paper show that well controlled target cargo release using polymersomes can be achieved with polymers of suitable design and can potentially be very useful for engineering applications. As an example, polymersomes can be used as carriers for surface active friction reducing additives which are only released at rubbing surfaces where the additives are needed most.

Biocompatible Electroactive Tetra(aniline)-Conjugated Peptide Nanofibers for Neural Differentiation

Peripheral nerve injuries cause devastating problems for the quality of patients' lives, and regeneration following damage to the peripheral nervous system is limited depending on the degree of the damage. Use of nanobiomaterials can provide therapeutic approaches for the treatment of peripheral nerve injuries. Electroactive biomaterials, in particular, can provide a promising cure for the regeneration of nerve defects. Here, a supramolecular electroactive nanosystem with tetra(aniline) (TA)-containing peptide nanofibers was developed and utilized for nerve regeneration. Self-assembled TA-conjugated peptide nanofibers demonstrated electroactive behavior. The electroactive self-assembled peptide nanofibers formed a well-defined three-dimensional nanofiber network mimicking the extracellular matrix of the neuronal cells. Neurite outgrowth was improved on the electroactive TA nanofiber gels. The neural differentiation of PC-12 cells was more advanced on electroactive peptide nanofiber gels, and these biomaterials are promising for further use in therapeutic neural regeneration applications.

A pH-responsive polymer based on dynamic imine bonds as a drug delivery material with pseudo target release behavior

In this study, pentaerythritol tetra(3-mercaptopropionate)-allylurea-poly(ethylene glycol) (PETMP-AU-PEG), produced by the Schiff-base reaction between terminal-aldehyded PEG and PETMP-AU, was used to prepare doxorubicin (DOX)-loaded polymers for triggered release.

Nano-engineered electro-responsive drug delivery systems

Nano-engineering is exploited to address the slow drug release and low drug loading of electro-responsive drug delivery systems.

A triblock terpolymer vs. blends of diblock copolymers for nanocapsules addressed by three independent stimuli

The chemical structure of triblock terpolymers is exploited to achieve polymer nanocapsules responsive to three different stimuli.

Trigger chemistries for better industrial formulations

In recent years, innovations and consumer demands have led to increasingly complex liquid formulations. These growing complexities have provided industrial players and their customers access to new markets through product differentiation, improved performance, and compatibility/stability with other products. One strategy for enabling more complex formulations is the use of active encapsulation. When encapsulation is employed, strategies are required to effect the release of the active at the desired location and time of action. One particular route that has received significant academic research effort is the employment of triggers to induce active release upon a specific stimulus, though little has translated for industrial use to date. To address emerging industrial formulation needs, in this review, we discuss areas of trigger release chemistries and their applications specifically as relevant to industrial use. We focus the discussion on the use of heat, light, shear, and pH triggers as applied in several model polymeric systems for inducing active release. The goal is that through this review trends will emerge for how technologies can be better developed to maximize their value through industrial adaptation.

Electrochemical potential-responsive tetra(aniline) nanocapsules via self-assembly

A new strategy is developed for electrochemical potential-responsive tetra(aniline) vesicles with tunable size via self-assembly.