α-Tocopherol liposome loaded chitosan hydrogel to suppress oxidative stress injury in cardiomyocytes

Novel injectable sodium alginate hydrogel developed for improved endometrial repair with human umbilical cord mesenchymal stem cells

This study presents a novel injectable sodium alginate hydrogel designed to enhanc stem cell therapy for endometrial regeneration. Using calcium gluconate as a crosslinking agent, we achieved improved homogeneity and injectability compared to traditional calcium chloride crosslinking. RGD modification further enhanced cell adhesion, proliferation, and differentiation in vitro, creating a bioactive scaffold for umbilical cord mesenchymal stem cells (UCMSCs) delivery. In a mouse model of endometrial injury, intrauterine transplantation of RGD-modified hydrogel encapsulating UCMSCs significantly improved endometrial thickness, reduced fibrosis, enhanced angiogenesis, and increased pregnancy rates compared to both untreated controls and UCMSCs alone. These results suggest that this injectable hydrogel system combined with stem cells holds significant promise for future applications in treating endometrial damage and improving reproductive outcomes in women.

Cosmetic emulsions containing innovative complex coacervates: A cross-sectional study

OBJECTIVE

Vitamin E, in the form of α-tocopherol (TOCO), is an essential lipophilic antioxidant widely used in topical formulations. However, incorporating pure TOCO into skincare products poses significant challenges due to its limited solubility and high sensitivity to heat, light and oxidation. The present cross-sectional study aimed to innovate by encapsulating TOCO using non-animal sustainable biopolymers through complex coacervation and to investigate the interaction of these coacervates with cosmetic emulsions, focusing on their impact on the emulsions' physicochemical properties and stability.

METHODS

TOCO was encapsulated using the complex coacervation technique by combining two biopolymers: fungal chitosan and gum Arabic. The designed microcapsules were incorporated into oil-in-water emulsions containing natural ingredients, and the physicochemical properties as well as the stability of the formulations were evaluated and compared to those of non-encapsulated TOCO emulsions.

RESULTS

Innovative coacervates of the non-animal TOCO complex of 86.8 ± 3.5 μm were developed, achieving a high encapsulation efficiency and loading of 87.0% and 27.2%, respectively. The microcapsules exhibited thermal stability up to a temperature of 220°C and showed improved storage stability of the active ingredient when encapsulated. In particular, 63% of TOCO was retained over 2 months at a temperature of 40°C. Emulsions containing microcapsules showed increased particle size distribution, higher viscosity, and enhanced viscoelastic properties, in accordance with their textural properties. Both emulsions remained stable for a 1-month storage period at a temperature of 40°C, and no noticeable effect of coacervates on the stability of TOCO in the emulsions was observed.

CONCLUSION

This study emphasises the potential of fungal chitosan-gum Arabic coacervates as a sustainable substitute for animal-derived coacervates, demonstrating promising outcomes for the encapsulation of lipophilic actives. When incorporated into cosmetic emulsions, these coacervates enhanced the textural and rheological properties while preserving the TOCO stability over time. These findings suggest that the developed microcapsules offer considerable potential for the development of future skin-care products with enhanced functional properties.

Dynamic and quantitative assessment of quercetin for cardiac oxidative stress injury prevention using sensitive cardiomyocyte based biosensing

Myocardial infarction is a leading cause of morbidity and mortality associated with cardiovascular diseases worldwide. Although novel medications and treatments greatly alleviate patient suffering, challenges related to prognostic limit the recovery of cardiac function. Currently, treatment with monomeric compounds displays promise in prognostic interventions for cardiac diseases. However, there is a lack of dynamic and quantitative assessment of cardiomyocyte response to these drugs. Herein, an integrated biosensing platform with a microelectrode array was constructed for label-free, non-invasive, long-term, and real-time recording of cardiomyocyte electrophysiological signals. By analyzing the signals of cardiomyocytes before and after treatment, we established the safe concentration of quercetin in cardiomyocytes and identified its long-term cardiotoxicity. Moreover, quercetin also demonstrated significant protective effects on cardiomyocytes in a H2O2-induced oxidative stress injury model. This study provides a trustworthy platform to evaluate the effects of monomeric compounds on cardiomyocytes, and offers a novel approach for drug screening and efficacy testing in cardiovascular diseases.

Unlocking the Potential of Hybrid Nanocomposite Hydrogels: Design, Mechanical Properties and Biomedical Performances

Hybrid nanocomposite hydrogels consist of the homogeneous incorporation of nano‐objects in a hydrogel matrix. The latter, whether made of natural or synthetic materials, possesses a microporous, soft structure that makes it an ideal host for a variety of polymer and lipid‐based nano‐objects as well as metal‐ and silica‐based ones. By carefully choosing the composition and the proportions of the different constituents, hybrid hydrogels can display a wide array of properties, from simple enhancement of mechanical characteristics to specific bioactivity. This review aims to provide an overview of the state of the art in hybrid hydrogels highlighting key aspects that make them a promising choice for a variety of biomedical applications. Strategies for the preparation of hybrid hydrogels are discussed by covering the selection of individual components. The review will also explore the physico‐chemical and rheological characterization of these materials, which is essential for understanding their structure and function, ultimately satisfying specifications for the intended use. Successful examples of biomedical applications will also be presented, and the main challenges to be met will be discussed, with the aim of stimulating the research community to exploit the full potential of these materials.

Improving the Stability, Water Solubility, and Antioxidant Activity of α-Tocopherol by Encapsulating It into Niosomes Modified with Cationic Carbamate-Containing Surfactants

The low solubility of α-tocopherol in water and its susceptibility to photodegradation make it difficult for biological systems to absorb this natural antioxidant. To overcome these limitations, α-tocopherol was encapsulated in low-toxicity nanocontainers, namely, niosomes based on Tween 80 and cholesterol. The niosomes were modified with cationic surfactants containing a carbamate fragment. The size and charge of the particles were determined and their stability was assessed using dynamic and electrophoretic light scattering methods. It was found that the introduction of cationic surfactants to niosome formulations significantly improved their physicochemical properties and increased stability due to a positive charge of up to +40 mV being generated. Modified niosomes loaded with α-tocopherol were characterized by a hydrodynamic diameter of 100-120 nm, a narrow particle size distribution, and a high encapsulation efficiency of more than 90%. Testing the photochemical stability of α-tocopherol using a spectrophotometric method demonstrated that niosomes were able to protect this substance from UV irradiation. Luminescence analysis showed that the inclusion of α-tocopherol in niosomes increased their antioxidant activity by 30%. An acute toxicity study has demonstrated the safety of the systems. The LD50 value for niosomes modified with carbamate-containing surfactants and loaded with α-tocopherol exceeded 10,000 mg·kg-1 (mice, intraperitoneal and oral administration).

A Mesoporous Silica-Loaded Multi-Functional Hydrogel Enhanced Tendon Healing via Immunomodulatory and Pro-Regenerative Effects

Tendon injuries are pervasive orthopedic injuries encountered by the general population. Nonetheless, recovery after severe injuries, such as Achilles tendon injury, is limited. Consequently, there is a pressing need to devise interventions, including biomaterials, that foster tendon healing. Regrettably, tissue engineering treatments have faced obstacles in crafting appropriate tissue scaffolds and efficacious nanomedical approaches. To surmount these hurdles, an innovative injectable hydrogel (CP@SiO2), comprising puerarin and chitosan through in situ self-assembly, is pioneered while concurrently delivering mesoporous silica nanoparticles for tendon healing. In this research, CP@SiO2 hydrogel is employed for the treatment of Achilles tendon injuries, conducting extensive in vivo and in vitro experiments to evaluate its efficacy. This reults demonstrates that CP@SiO2 hydrogel enhances the proliferation and differentiation of tendon-derived stem cells, and mitigates inflammation through the modulation of macrophage polarization. Furthermore, using histological and behavioral analyses, it is found that CP@SiO2 hydrogel can improve the histological and biomechanical properties of injured tendons. This findings indicate that this multifaceted injectable CP@SiO2 hydrogel constitutes a suitable bioactive material for tendon repair and presents a promising new strategy for the clinical management of tendon injuries.

Injectable Liposome-Loaded Hydrogel Formulations with Controlled Release of Curcumin and α-Tocopherol for Dental Tissue Engineering

An injectable hydrogel formulation is developed utilizing low- and high-molecular-weight chitosan (LCH and HCH) incorporated with curcumin and α-tocopherol-loaded liposomes (Lip/Cur+Toc). Cur and Toc releases are delayed within the hydrogels. The injectability of hydrogels is proved via rheological analyses. In vitro studies are conducted using human dental pulp stem cells (hDPSCs) and human gingival fibroblasts (hGFs) to examine the biological performance of the hydrogels toward endodontics and periodontics, respectively. The viability of hDPSCs treated with the hydrogels with Lip/Cur+Toc is the highest till day 14, compared to the neat hydrogels. During odontogenic differentiation tests, alkaline phosphatase (ALP) enzyme activity of hDPSCs is induced in the Cur-containing groups. Biomineralization is enhanced mostly with Lip/Cur+Toc incorporation. The viability of hGFs is the highest in HCH combined with Lip/Cur+Toc while wound healing occurs almost 100% in both (Lip/Cur+Toc@LCH and Lip/Cur+Toc@HCH) after 2 days. Antioxidant activity of Lip/Cur+Toc@LCH on hGFs is significantly the highest among the groups. Antimicrobial tests demonstrate that Lip/Cur+Toc@LCH is more effective against Escherichia coli whereas so is Lip/Cur+Toc@HCH against Staphylococcus aureus. The antimicrobial mechanism of the hydrogels is investigated for the first time through various computational models. LCH and HCH loaded with Lip/Cur+Toc are promising candidates with multi-functional features for endodontics and periodontics.

Hydrogel delivery systems of functional substances for precision nutrition

Hydrogel delivery systems based on polysaccharides and proteins have the ability to protect functional substances from chemical degradation, control/target release, and increase bioavailability. This chapter summarizes the recent progress in the utilization of hydrogel delivery systems for nutritional interventions. Various hydrogel delivery systems as well as their preparation, structure, and properties are given. The applications for the encapsulation, protection, and controlled delivery of functional substances are described. We also discuss their potential and challenges in managing chronic diseases such as inflammatory bowel disease, obesity, liver disease, and cancer, aiming at providing theoretical references for exploring novel hydrogel delivery systems and their practical prospects in precise nutritional interventions.

Advanced Cardiac Patches for the Treatment of Myocardial Infarction

Myocardial infarction is a cardiovascular disease characterized by a high incidence rate and mortality. It leads to various cardiac pathophysiological changes, including ischemia/reperfusion injury, inflammation, fibrosis, and ventricular remodeling, which ultimately result in heart failure and pose a significant threat to global health. Although clinical reperfusion therapies and conventional pharmacological interventions improve emergency survival rates and short-term prognoses, they are still limited in providing long-lasting improvements in cardiac function or reversing pathological progression. Recently, cardiac patches have gained considerable attention as a promising therapy for myocardial infarction. These patches consist of scaffolds or loaded therapeutic agents that provide mechanical reinforcement, synchronous electrical conduction, and localized delivery within the infarct zone to promote cardiac restoration. This review elucidates the pathophysiological progression from myocardial infarction to heart failure, highlighting therapeutic targets and various cardiac patches. The review considers the primary scaffold materials, including synthetic, natural, and conductive materials, and the prevalent fabrication techniques and optimal properties of the patch, as well as advanced delivery strategies. Last, the current limitations and prospects of cardiac patch research are considered, with the goal of shedding light on innovative products poised for clinical application.

The application strategy of liposomes in organ targeting therapy

Liposomes-microscopic phospholipid bubbles with bilayered membrane structure-have been a focal point in drug delivery research for the past 30 years. Current liposomes possess a blend of biocompatibility, drug loading efficiency, prolonged circulation and targeted delivery. Tailored liposomes, varying in size, charge, lipid composition, and ratio, have been developed to address diseases in specific organs, thereby enhancing drug circulation, accumulation at lesion sites, intracellular delivery, and treatment efficacy for various organ-specific diseases. For further successful development of this field, this review summarized liposomal strategies for targeting different organs in series of major human diseases, including widely studied cardiovascular diseases, liver and spleen immune diseases, chronic or acute kidney injury, neurodegenerative diseases, and organ-specific tumors. It highlights recent advances of liposome-mediated therapeutic agent delivery for disease intervention and organ rehabilitation, offering practical guidelines for designing organ-targeted liposomes. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Biology-Inspired Nanomaterials > Lipid-Based Structures.

Chitosan-Polyethylene Glycol Inspired Polyelectrolyte Complex Hydrogel Templates Favoring NEO-Tissue Formation for Cardiac Tissue Engineering

Neo-tissue formation and host tissue regeneration determine the success of cardiac tissue engineering where functional hydrogel scaffolds act as cardiac (extracellular matrix) ECM mimic. Translationally, the hydrogel templates promoting neo-cardiac tissue formation are currently limited; however, they are highly demanding in cardiac tissue engineering. The current study focused on the development of a panel of four chitosan-based polyelectrolyte hydrogels as cardiac scaffolds facilitating neo-cardiac tissue formation to promote cardiac regeneration. Chitosan-PEG (CP), gelatin-chitosan-PEG (GCP), hyaluronic acid-chitosan-PEG (HACP), and combined CP (CoCP) polyelectrolyte hydrogels were engineered by solvent casting and assessed for physiochemical, thermal, electrical, biodegradable, mechanical, and biological properties. The CP, GCP, HACP, and CoCP hydrogels exhibited excellent porosity (4.24 ± 0.18, 13.089 ± 1.13, 12.53 ± 1.30 and 15.88 ± 1.10 for CP, GCP, HACP and CoCP, respectively), water profile, mechanical strength, and amphiphilicity suitable for cardiac tissue engineering. The hydrogels were hemocompatible as evident from the negligible hemolysis and RBC aggregation and increased adsorption of plasma albumin. The hydrogels were cytocompatible as evident from the increased viability by MTT (>94% for all the four hydrogels) assay and direct contact assay. Also, the hydrogels supported the adhesion, growth, spreading, and proliferation of H9c2 cells as unveiled by rhodamine staining. The hydrogels promoted neo-tissue formation that was proven using rat and swine myocardial tissue explant culture. Compared to GCP and CoCP, CP and HACP were superior owing to the cell viability, hemocompatibility, and conductance, resulting in the highest degree of cytoskeletal organization and neo-tissue formation. The physiochemical and biological performance of these hydrogels supported neo-cardiac tissue formation. Overall, the CP, GCP, HACP, and CoCP hydrogel systems promise novel translational opportunities in regenerative cardiology.

Biomaterials-Based Antioxidant Strategies for the Treatment of Oxidative Stress Diseases

Oxidative stress is characterized by an increase in reactive oxygen species or a decrease in antioxidants in the body. This imbalance leads to detrimental effects, including inflammation and multiple chronic diseases, ranging from impaired wound healing to highly impacting pathologies in the neural and cardiovascular systems, or the bone, amongst others. However, supplying compounds with antioxidant activity is hampered by their low bioavailability. The development of biomaterials with antioxidant capacity is poised to overcome this roadblock. Moreover, in the treatment of chronic inflammation, material-based strategies would allow the controlled and targeted release of antioxidants into the affected tissue. In this review, we revise the main causes and effects of oxidative stress, and survey antioxidant biomaterials used for the treatment of chronic wounds, neurodegenerative diseases, cardiovascular diseases (focusing on cardiac infarction, myocardial ischemia-reperfusion injury and atherosclerosis) and osteoporosis. We anticipate that these developments will lead to the emergence of new technologies for tissue engineering, control of oxidative stress and prevention of diseases associated with oxidative stress.

Bacterial Cellulose-Based Materials: A Perspective on Cardiovascular Tissue Engineering Applications

Today, a wide variety of bio- and nanomaterials have been deployed for cardiovascular tissue engineering (TE), including polymers, metal oxides, graphene/its derivatives, organometallic complexes/composites based on inorganic-organic components, among others. Despite several advantages of these materials with unique mechanical, biological, and electrical properties, some challenges still remain pertaining to their biocompatibility, cytocompatibility, and possible risk factors (e.g., teratogenicity or carcinogenicity), restricting their future clinical applications. Natural polysaccharide- and protein-based (nano)structures with the benefits of biocompatibility, sustainability, biodegradability, and versatility have been exploited in the field of cardiovascular TE focusing on targeted drug delivery, vascular grafts, engineered cardiac muscle, etc. The usage of these natural biomaterials and their residues offers several advantages in terms of environmental aspects such as alleviating emission of greenhouse gases as well as the production of energy as a biomass consumption output. In TE, the development of biodegradable and biocompatible scaffolds with potentially three-dimensional structures, high porosity, and suitable cellular attachment/adhesion still needs to be comprehensively studied. In this context, bacterial cellulose (BC) with high purity, porosity, crystallinity, unique mechanical properties, biocompatibility, high water retention, and excellent elasticity can be considered as promising candidate for cardiovascular TE. However, several challenges/limitations regarding the absence of antimicrobial factors and degradability along with the low yield of production and extensive cultivation times (in large-scale production) still need to be resolved using suitable hybridization/modification strategies and optimization of conditions. The biocompatibility and bioactivity of BC-based materials along with their thermal, mechanical, and chemical stability are crucial aspects in designing TE scaffolds. Herein, cardiovascular TE applications of BC-based materials are deliberated, with a focus on the most recent advancements, important challenges, and future perspectives. Other biomaterials with cardiovascular TE applications and important roles of green nanotechnology in this field of science are covered to better compare and comprehensively review the subject. The application of BC-based materials and the collective roles of such biomaterials in the assembly of sustainable and natural-based scaffolds for cardiovascular TE are discussed.

Current Applications of Liposomes for the Delivery of Vitamins: A Systematic Review

Liposomes have been used for several decades for the encapsulation of drugs and bioactives in cosmetics and cosmeceuticals. On the other hand, the use of these phospholipid vesicles in food applications is more recent and is increasing significantly in the last ten years. Although in different stages of technological maturity-in the case of cosmetics, many products are on the market-processes to obtain liposomes suitable for the encapsulation and delivery of bioactives are highly expensive, especially those aiming at scaling up. Among the bioactives proposed for cosmetics and food applications, vitamins are the most frequently used. Despite the differences between the administration routes (oral for food and mainly dermal for cosmetics), some challenges are very similar (e.g., stability, bioactive load, average size, increase in drug bioaccessibility and bioavailability). In the present work, a systematic review of the technological advancements in the nanoencapsulation of vitamins using liposomes and related processes was performed; challenges and future perspectives were also discussed in order to underline the advantages of these drug-loaded biocompatible nanocarriers for cosmetics and food applications.

An injectable hydrogel combining medicine and matrix with anti-inflammatory and pro-angiogenic properties for potential treatment of myocardial infarction

One of the main illnesses that put people's health in jeopardy is myocardial infarction (MI). After MI, damaged or dead cells set off an initial inflammatory response that thins the ventricle wall and degrades the extracellular matrix. At the same time, the ischemia and hypoxic conditions resulting from MI lead to significant capillary obstruction and rupture, impairing cardiac function and reducing blood flow to the heart. Therefore, attenuating the initial inflammatory response and promoting angiogenesis are very important for the treatment of MI. Here, to reduce inflammation and promote angiogenesis in infarcted area, we report a new kind of injectable hydrogel composed of puerarin and chitosan via in situ self-assembly with simultaneous delivery of mesoporous silica nanoparticles (CHP@Si) for myocardial repair. On the one hand, puerarin degraded from CHP@Si hydrogel modulated the inflammatory response via inhibiting M1-type polarization of macrophages and expression of pro-inflammatory factors. On the other hand, silica ions and puerarin released from CHP@Si hydrogel showed synergistic activity to improve the cell viability, migration and angiogenic gene expression of HUVECs in both conventional and oxygen/glucose-deprived environments. It suggests that this multifunctional injectable CHP@Si hydrogel with good biocompatibility may be an appropriate candidate as a bioactive material for myocardial repair post-MI.

A chitosan-vitamin C based injectable hydrogel improves cell survival under oxidative stress

Stem cell transplantation technology provides the cell reconstruction of damaged heart a completely new therapy approach. Due to the inappropriate microenvironment such as reactive oxygen radicals caused by ischemic infarct, the survival and retention rates of cell transplantation are not desirable. A thermo sensitive chitosan-vitamin C (CSVC) hydrogel scaffold was developed to reduce oxidative stress injury after myocardial infarction, thereby increasing the cell survival rate of cell transplantation. Vitamin C was conjugated on the chitosan chain by electrostatic adsorption. Compared to chitosan, CSVC complex had a higher solubility and stronger antioxidant property. CSVC hydrogel has suitable gelation time and injectable properties. Scanning electron microscopy showed that chitosan hydrogels had three-dimensional porous structure with irregular pores interconnected throughout the construct. Live/dead and H&E staining results showed that CSVC hydrogel can support the survival and adhesion of cardiomyocytes. Compared with chitosan hydrogel, CSVC hydrogel can clearly improve the survival of cardiomyocytes and reduce the ROS level under H₂O₂-induced oxidative stress conditions. These results suggest that CSVC hydrogel has the potential to support the survival of cardiomyocytes in tissue engineering.

Nanocarrier-hydrogel composite delivery systems for precision drug release

Hydrogels are a class of biomaterials widely implemented in medical applications due to their biocompatibility and biodegradability. Despite the many successes of hydrogel-based delivery systems, there remain challenges to hydrogel drug delivery such as a burst release at the time of administration, a limited ability to encapsulate certain types of drugs (i.e., hydrophobic drugs, proteins, antibodies, and nucleic acids), and poor tunability of geometry and shape for controlled drug release. This review discusses two main important advances in hydrogel fabrication for precision drug release: first, the incorporation of nanocarriers to diversify their drug loading capability, and second, the design of hydrogels using 3D printing to precisely control drug dosing and release kinetics via high-resolution structures and geometries. We also outline ongoing challenges and discuss opportunities to further optimize drug release from hydrogels for personalized medicine. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Nanomaterials: A Promising Therapeutic Approach for Cardiovascular Diseases

Cardiovascular diseases (CVDs) are a primary cause of death globally. A few classic and hybrid treatments exist to treat CVDs. However, they lack in both safety and effectiveness. Thus, innovative nanomaterials for disease diagnosis and treatment are urgently required. The tiny size of nanomaterials allows them to reach more areas of the heart and arteries, making them ideal for CVDs. Atherosclerosis causes arterial stenosis and reduced blood flow. The most common treatment is medication and surgery to stabilize the disease. Nanotechnologies are crucial in treating vascular disease. Nanomaterials may be able to deliver medications to lesion sites after being infused into the circulation. Newer point‐of‐care devices have also been considered together with nanomaterials. For example, this study will look at the use of nanomaterials in imaging, diagnosing, and treating CVDs.

Regenerative strategies for the consequences of myocardial infarction: Chronological indication and upcoming visions

Heart muscle injury and an elevated troponin level signify myocardial infarction (MI), which may result in defective and uncoordinated segments, reduced cardiac output, and ultimately, death. Physicians apply thrombolytic therapy, coronary artery bypass graft (CABG) surgery, or percutaneous coronary intervention (PCI) to recanalize and restore blood flow to the coronary arteries, albeit they were not convincingly able to solve the heart problems. Thus, researchers aim to introduce novel substitutional therapies for regenerating and functionalizing damaged cardiac tissue based on engineering concepts. Cell-based engineering approaches, utilizing biomaterials, gene, drug, growth factor delivery systems, and tissue engineering are the most leading studies in the field of heart regeneration. Also, understanding the primary cause of MI and thus selecting the most efficient treatment method can be enhanced by preparing microdevices so-called heart-on-a-chip. In this regard, microfluidic approaches can be used as diagnostic platforms or drug screening in cardiac disease treatment. Additionally, bioprinting technique with whole organ 3D printing of human heart with major vessels, cardiomyocytes and endothelial cells can be an ideal goal for cardiac tissue engineering and remarkable achievement in near future. Consequently, this review discusses the different aspects, advancements, and challenges of the mentioned methods with presenting the advantages and disadvantages, chronological indications, and application prospects of various novel therapeutic approaches.

Hydrogel, a novel therapeutic and delivery strategy, in the treatment of intrauterine adhesions

Intrauterine adhesions (IUAs) are caused by damage to the underlying lining of the endometrium. They' re related to disorder of endometrial repair. In recent years, hydrogels with controllable biological activity have been widely used for treating IUAs. They encapsulate estrogen, cytokines, cells, or exosomes, forming a delivery system to release therapeutic components for the treatment of IUAs. In addition, the hydrogel acting as a barrier can be degraded in the body automatically, reducing the risk of infection caused by secondary surgeries. In this review, we summarize the recent progress of hydrogels and their application in IUAs as both a novel alternative therapeutic and an artificial delivery strategy.

Vitamin E: A Review of Its Application and Methods of Detection When Combined with Implant Biomaterials

Vitamin E is a common compound used for tocopherols and tocotrienols (α, β, γ, δ); it is the component of many natural products of both plant and animal origin. Thanks to its powerful antioxidant capacity, vitamin E has been very successful in hip and knee arthroplasty, used to confer resistance to oxidation to irradiated UHMWPE. The positive results of these studies have made vitamin E an important object of research in the biomedical field, highlighting other important properties, such as anti-bacterial, -inflammatory, and -cancer activities. In fact, there is an extensive literature dealing with vitamin E in different kinds of material processing, drug delivery, and development of surface coatings. Vitamin E is widely discussed in the literature, and it is possible to find many reviews that discuss the biological role of vitamin E and its applications in food packaging and cosmetics. However, to date, there is not a review that discusses the biomedical applications of vitamin E and that points to the methods used to detect it within a solid. This review specifically aims to compile research about new biomedical applications of vitamin E carried out in the last 20 years, with the intention of providing an overview of the methodologies used to combine it with implantable biomaterials, as well as to detect and characterize it within these materials.

Biopolymer-liposome hybrid systems for controlled delivery of bioactive compounds: Recent advances

Conventional liposomes still face many challenges associated with the poor physical and chemical stability, considerable loss of encapsulated cargo, lack of stimulus responsiveness, and rapid elimination from blood circulation. Integration of versatile functional biopolymers has emerged as an attractive strategy to overcome the limitation of usage of liposomes. This review comprehensively summarizes the most recent studies (2015-2020) and their challenges aiming at the exploration of biopolymer-liposome hybrid systems, including surface-modified liposomes, biopolymer-incorporated liposomes, guest-in-cyclodextrin-in-liposome, liposome-in-hydrogel, liposome-in-film, and liposome-in-nanofiber. The physicochemical principles and key technical information underlying the combined strategies for the fabrication of polymeric liposomes, the advantages and limitations of each of the systems, and the stabilization mechanisms are discussed through various case studies. Special emphasis is directed toward the synergistic efficiencies of biopolymers and phospholipid bilayers on encapsulation, protection, and controlled delivery of bioactives (e.g., vitamins, carotenoids, phenolics, peptides, and other health-related compounds) for the biomedical, pharmaceutical, cosmetic, and functional food applications. The major challenges, opportunities, and possible further developments for future studies are also highlighted.

Nanocarriers for drug delivery to the inner ear: Physicochemical key parameters, biodistribution, safety and efficacy

Despite the high incidence of inner ear disorders, there are still no dedicated medications on the market. Drugs are currently administered by the intratympanic route, the safest way to maximize drug concentration in the inner ear. Nevertheless, therapeutic doses are ensured for only a few minutes/hours using drug solutions or suspensions. The passage through the middle ear barrier strongly depends on drug physicochemical characteristics. For the past 15 years, drug encapsulation into nanocarriers has been developed to overcome this drawback. Nanocarriers are well known to sustain drug release and protect it from degradation. In this review, in vivo studies are detailed concerning nanocarrier biodistribution, their pathway mechanisms in the inner ear and the resulting drug pharmacokinetics. Key parameters influencing nanocarrier biodistribution are identified and discussed: nanocarrier size, concentration, surface composition and shape. Recent advanced strategies that combine nanocarriers with hydrogels, specific tissue targeting or modification of the round window permeability (cell-penetrating peptide, magnetic delivery) are explored. Most of the nanocarriers appear to be safe for the inner ear and provide a significant efficacy over classic formulations in animal models. However, many challenges remain to be overcome for future clinical applications.

Engineering Smart Targeting Nanovesicles and Their Combination with Hydrogels for Controlled Drug Delivery

Smart engineered and naturally derived nanovesicles, capable of targeting specific tissues and cells and delivering bioactive molecules and drugs into them, are becoming important drug delivery systems. Liposomes stand out among different types of self-assembled nanovesicles, because of their amphiphilicity and non-toxic nature. By modifying their surfaces, liposomes can become stimulus-responsive, releasing their cargo on demand. Recently, the recognized role of exosomes in cell-cell communication and their ability to diffuse through tissues to find target cells have led to an increase in their usage as smart delivery systems. Moreover, engineering "smarter" delivery systems can be done by creating hybrid exosome-liposome nanocarriers via membrane fusion. These systems can be loaded in naturally derived hydrogels to achieve sustained and controlled drug delivery. Here, the focus is on evaluating the smart behavior of liposomes and exosomes, the fabrication of hybrid exosome-liposome nanovesicles, and the controlled delivery and routes of administration of a hydrogel matrix for drug delivery systems.

Repositioning Natural Antioxidants for Therapeutic Applications in Tissue Engineering

Although a large panel of natural antioxidants demonstrate a protective effect in preventing cellular oxidative stress, their low bioavailability limits therapeutic activity at the targeted injury site. The importance to deliver drug or cells into oxidative microenvironments can be realized with the development of biocompatible redox-modulating materials. The incorporation of antioxidant compounds within implanted biomaterials should be able to retain the antioxidant activity, while also allowing graft survival and tissue recovery. This review summarizes the recent literature reporting the combined role of natural antioxidants with biomaterials. Our review highlights how such functionalization is a promising strategy in tissue engineering to improve the engraftment and promote tissue healing or regeneration.

Roles of Reactive Oxygen Species in Cardiac Differentiation, Reprogramming, and Regenerative Therapies

Reactive oxygen species (ROS) have been implicated in mechanisms of heart development and regenerative therapies such as the use of pluripotent stem cells. The roles of ROS mediating cell fate are dependent on the intensity of stimuli, cellular context, and metabolic status. ROS mainly act through several targets (such as kinases and transcription factors) and have diverse roles in different stages of cardiac differentiation, proliferation, and maturation. Therefore, further detailed investigation and characterization of redox signaling will help the understanding of the molecular mechanisms of ROS during different cellular processes and enable the design of targeted strategies to foster cardiac regeneration and functional recovery. In this review, we focus on the roles of ROS in cardiac differentiation as well as transdifferentiation (direct reprogramming). The potential mechanisms are discussed in regard to ROS generation pathways and regulation of downstream targets. Further methodological optimization is required for translational research in order to robustly enhance the generation efficiency of cardiac myocytes through metabolic modulations. Additionally, we highlight the deleterious effect of the host's ROS on graft (donor) cells in a paracrine manner during stem cell-based implantation. This knowledge is important for the development of antioxidant strategies to enhance cell survival and engraftment of tissue engineering-based technologies. Thus, proper timing and level of ROS generation after a myocardial injury need to be tailored to ensure the maximal efficacy of regenerative therapies and avoid undesired damage.

Antioxidant Activity of Encapsulated Extracts and Bioactives from Natural Sources

The low water solubility and low bioavailability of natural bioactive substances such as polyphenols and flavonoids, either in pure form or extracts, are a major concern in the pharmaceutical field and even on the food development sector. Although encapsulation has demonstrated success in addressing these drawbacks, it is important to evaluate the antioxidant activity of the encapsulated compounds. This article reviews the encapsulation of bioactive compounds from natural sources focusing their antioxidant activity after encapsulation. Attention is given to the methods and wall materials used, and the antioxidant activity methodologies (classical in vitro techniques such as DPPH, ORAC, FRAP and others, as well as in vivo/ex vivo tests to evaluate endogenous antioxidant enzymes or oxidative stress) applied to assess the antioxidant capacity are also comprehensively summarized.

Simil-Microfluidic Nanotechnology in Manufacturing of Liposomes as Hydrophobic Antioxidants Skin Release Systems

Novel nanotechnologies represent the most attractive and innovative tools to date exploited by cosmetic companies to improve the effectiveness of their formulations. In this context, nanoliposomes have had a great impact in topical preparations and dermocosmetics, allowing the transcutaneous penetration and absorption of several active ingredients and improving the stability of sensitive molecules. Despite the recent boom of this class of delivery systems, their industrial production is still limited by the lack of easily scalable production techniques. In this work, nanoliposomes for the topical administration of vitamin D3, K2, E, and curcumin, molecules with high antioxidant and skin curative properties but unstable and poorly absorbable, were produced through a novel simil-microfluidic technique. The developed high-yield semi continuous method is proposed as an alternative to face the problems linked with low productive conventional methods in order to produce antioxidant formulations with improved features. The novel technique has allowed to obtain a massive production of stable antioxidant vesicles of an 84–145 nm size range, negatively charged, and characterized by high loads and encapsulation efficiencies. The obtained products as well as the developed high-performance technology make the achieved formulations very interesting for potential topical applications in the cosmetics/cosmeceutical field.

Injectable Hydrogel-Based Nanocomposites for Cardiovascular Diseases

Cardiovascular diseases (CVDs), including a series of pathological disorders, severely affect millions of people all over the world. To address this issue, several potential therapies have been developed for treating CVDs, including injectable hydrogels as a minimally invasive method. However, the utilization of injectable hydrogel is a bit restricted recently owing to some limitations, such as transporting the therapeutic agent more accurately to the target site and prolonging their retention locally. This review focuses on the advances in injectable hydrogels for CVD, detailing the types of injectable hydrogels (natural or synthetic), especially that complexed with stem cells, cytokines, nano-chemical particles, exosomes, genetic material including DNA or RNA, etc. Moreover, we summarized the mainly prominent mechanism, based on which injectable hydrogel present excellent treating effect of cardiovascular repair. All in all, it is hopefully that injectable hydrogel-based nanocomposites would be a potential candidate through cardiac repair in CVDs treatment.

Potential application of liposomal nanodevices for non-cancer diseases: an update on design, characterization and biopharmaceutical evaluation

Liposomes, lipid-based vesicular systems, have attracted major interest as a means to improve drug delivery to various organs and tissues in the human body. Recent literature highlights the benefits of liposomes for use as drug delivery systems, including encapsulating of both hydrophobic and hydrophilic cargos, passive and active targeting, enhanced drug bioavailability and therapeutic effects, reduced systemic side effects, improved cargo penetration into the target tissue and triggered contents release. Pioneering work of liposomes researchers led to introduction of long-circulating, ligand-targeted and triggered release liposomes, as well as, liposomes containing nucleic acids and vesicles containing combination of cargos. Altogether, these findings have led to widespread application of liposomes in a plethora of areas from cancer to conditions such as cardiovascular, neurologic, respiratory, skin, autoimmune and eye disorders. There are numerous review articles on the application of liposomes in treatment of cancer, which seems the primary focus, whereas other diseases also benefit from liposome-mediated treatments. Therefore, this article provides an illustrated detailed overview of liposomal formulations, in vitro characterization and their applications in different disorders other than cancer. Challenges and future directions, which must be considered to obtain the most benefit from applications of liposomes in these disorders, are discussed.

An injectable thermosensitive hydrogel for sustained release of apelin-13 to enhance flap survival in rat random skin flap

With the advantage of handy process, random pattern skin flaps are generally applied in limb reconstruction and wound repair. Apelin-13 is a discovered endogenous peptide, that has been shown to have potent multiple biological functions. Recently, thermosensitive gel-forming systems have gained increasing attention as wound dressings due to their advantages. In the present study, an apelin-13-loaded chitosan (CH)/β-sodium glycerophosphate (β-GP) hydrogel was developed for promoting random skin flap survival. Random skin flaps were created in 60 rats after which the animals were categorized to a control hydrogel group and an apelin-13 hydrogel group. The water content of the flap as well as the survival area were then measured 7 days post-surgery. Hematoxylin and eosin staining was used to evaluate the flap angiogenesis. Cell differentiation 34 (CD34) and vascular endothelial growth factor (VEGF) levels were detected by immunohistochemistry and Western blotting. Tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were assessed by enzyme linked immunosorbent assays (ELISAs). Oxidative stress was estimated via the activity of tissue malondialdehyde (MDA) and superoxide dismutase (SOD). Our results showed that CH/β-GP/apelin-13 hydrogel could not only reduce the tissue edema, but also improve the survival area of flap. CH/β-GP/apelin-13 hydrogel also upregulated levels of VEGF protein and increased mean vessel densities. Furthermore, CH/β-GP/apelin-13 hydrogel was shown to significantly inhibit the expression of TNF-α and IL-6, along with increasing the activity of SOD and suppressing the MDA content. Taken together, these results indicate that this CH/β-GP/apelin-13 hydrogel may be a potential therapeutic way for random pattern skin flap.

Ectopic chondrogenesis of nude mouse induced by nano gene delivery enhanced tissue engineering technology

Background: Many techniques and methods have been used clinically to relieve pain from cartilage repair, but the long-term effect is still unsatisfactory. Purpose: The objective of this study was to form an artificial chondroid tissue gene enhanced tissue engineering system to repair cartilage defects via nanosized liposomes. Methods: Cationic nanosized liposomes were prepared and characterized using transmission electron microscope (TEM) and dynamic laser light scattering (DLS). The rat mesenchymal stem cells (rMSCs) were isolated, cultivated, and induced by SRY (Sex-Determining Region Y)-Box 9 (Sox9) via cationic nanosized liposomes. The induced rMSCs were mixed with a thermo-sensitive chitosan hydrogel and subcutaneously injected into the nude mice. Finally, the newly-formed chondroid tissue obtained in the injection parts, and the transparent parts were detected by HE, collagen II, and safranin O. Results: It was found that the presently prepared cationic nanosized liposomes had the diameter of 85.76±3.48 nm and the zeta potential of 15.76±2.1 mV. The isolated rMSCs proliferation was fibroblast-like, with a cultivated confluence of 90% confluence in 5-8 days, and stained positive for CD29 and CD44 while negative for CD34 and CD45. After transfection with cationic nanosized liposomes, we observed changes of cellular morphology and a higher expression of SOX9 compared with control groups, which indicated that rMSCs could differentiate into chondrocyte in vitro. By mixing transfected rMSCs with the thermo-sensitive hydrogel of chitosan in nude mice, chondroid tissue was successfully obtained, demonstrating that rMSCs can differentiate into chondrogenic cells in vivo. Conclusion: This study explored new ways to improve the quality of tissue engineered cartilage, thus accelerating clinical transformation and reducing patient pain.