Cerium Oxide Nanoparticles Absorption through Intact and Damaged Human Skin

Accumulation of rare earth elements in human gallstones: a perspective from dietary and human health

BACKGROUND

Gallstone disease poses a global threat to human health and is strongly linked to environmental factors. However, there is currently no data on the presence of rare earth elements (REEs) in human gallstones. This paper investigates the concentration and distribution of REEs in gallstones for the first time, aiming to explore the environmental implications on human health.

METHODS

A total of 25 gallstone samples were collected in Shanghai and the content of REEs was measured by Inductively coupled plasma-Mass Spectrometry (ICP-MS) to explore the distribution of REEs in gallstones.

RESULTS

The concentration of REEs in gallstones ranged from 4.89 to 190.8 ng/g (mean 39.21). In most of the gallstone analyses, REEs have been detected and generally attributed to environmental exposure or food contamination. The Y/Ho ratio of gallstones was lower than that of continental rocks, similar to that in the blood, indicating limited fractionation during fluid transport processes in the gallbladder.

CONCLUSIONS

The upper continental crust (UCC)-normalized REEs pattern in gallstones showed depletion of light REEs, while most showed enrichment of heavy REEs. Positive Gd anomalies were found in most samples, while few samples suggested anthropogenic influence. Whether exogenous inputs or in vivo biofractionation lead to changes in REEs fractionated patterns require further analyses.

Toxic Effects of Rare Earth Elements on Human Health: A Review

Rare earth elements (REEs) are a new type of material resource which have attracted significant attention in recent years. REEs have emerged as essential metals in modern-day technology due to their unique functions. The long-term, large-scale mining and utilization of rare earths has caused serious environmental pollution and constitutes a global health issue, which has raised concerns regarding the safety of human health. However, the toxicity profile of suspended particulate matter in REEs in the environment, which interacts with the human body, remains largely unknown. Studies have shown that REEs can enter the human body through a variety of pathways, leading to a variety of organ and system dysfunctions through changes in genetics, epigenetics, and signaling pathways. Through an extensive literature search and critical analysis, we provide a comprehensive overview of the available evidence, identify knowledge gaps, and make recommendations for future research directions.

Systematic review of the osteogenic effect of rare earth nanomaterials and the underlying mechanisms

Rare earth nanomaterials (RE NMs), which are based on rare earth elements, have emerged as remarkable biomaterials for use in bone regeneration. The effects of RE NMs on osteogenesis, such as promoting the osteogenic differentiation of mesenchymal stem cells, have been investigated. However, the contributions of the properties of RE NMs to bone regeneration and their interactions with various cell types during osteogenesis have not been reviewed. Here, we review the crucial roles of the physicochemical and biological properties of RE NMs and focus on their osteogenic mechanisms. RE NMs directly promote the proliferation, adhesion, migration, and osteogenic differentiation of mesenchymal stem cells. They also increase collagen secretion and mineralization to accelerate osteogenesis. Furthermore, RE NMs inhibit osteoclast formation and regulate the immune environment by modulating macrophages and promote angiogenesis by inducing hypoxia in endothelial cells. These effects create a microenvironment that is conducive to bone formation. This review will help researchers overcome current limitations to take full advantage of the osteogenic benefits of RE NMs and will suggest a potential approach for further osteogenesis research.

Ceria-Based Therapeutic Antioxidants for Biomedical Applications

The growing interest in nanomedicine over the last 20 years has carved out a research field called "nanocatalytic therapy," where catalytic reactions mediated by nanomaterials are employed to intervene in disease-critical biomolecular processes. Among many kinds of catalytic/enzyme-mimetic nanomaterials investigated thus far, ceria nanoparticles stand out from others owing to their unique scavenging properties against biologically noxious free radicals, including reactive oxygen species (ROS) and reactive nitrogen species (RNS), by exerting enzyme mimicry and nonenzymatic activities. Much effort has been made to utilize ceria nanoparticles as self-regenerating antioxidative and anti-inflammatory agents for various kinds of diseases, given the detrimental effects of ROS and RNS therein that need alleviation. In this context, this review is intended to provide an overview as to what makes ceria nanoparticles merit attention in disease therapy. The introductory part describes the characteristics of ceria nanoparticles as an oxygen-deficient metal oxide. The pathophysiological roles of ROS and RNS are then presented, as well as their scavenging mechanisms by ceria nanoparticles. Representative examples of recent ceria-nanoparticle-based therapeutics are summarized by categorization into organ and disease types, followed by the discussion on the remaining challenges and future research directions.

Sensitive Cr3+ sensor based on novel poly(luminol-co-1,8-diaminonaphthalene)/CeO2/MWCNTs nanocomposites

In this study, poly(luminol-co-1,8-diaminonaphthalene) (PLim-DAN) was synthesized and subsequently modified with MWCNTs and CeO2 NPs. The synthesized nanocomposites were analyzed using IR, SEM, TEM, and XRD. Furthermore, a comprehensive set of thermal behavior measurements were taken using TGA/DTG analysis. Next, the electroactivity of the developed nanocomposites was tested as an electrochemical sensor to measure the concentration of Cr3+ ions in phosphate buffers. The GCE adapted with the PLim-DAN/CeO2/CNTs-10% nanocomposite (NC) exhibited the highest current response among the other compositions and copolymers. The fabricated nanocomposite sensor showed high sensitivity, with a value of 19.78 μA μM-1 cm-2, and a low detection limit of 4.80 ± 0.24 pM. The analytical performance was evaluated by plotting a current calibration curve versus the concentration of Cr3+ ions. It was found to be linear (R2 = 0.9908) over the range of 0.1 nM to 0.1 mM, identified as the linear dynamic range (LDR). This electrochemical sensor demonstrated that it could be a useful tool for environmental monitoring by accurately detecting and measuring carcinogenic Cr3+ ions in real-world samples.

The effectiveness of an intervention to reduce exposure to trace metals during or prior to pregnancy: A prospective study in urban and rural locations

Background

Prenatal exposure to trace metals can have adverse effects on health and increase the risk of developing certain diseases. This study aimed to determine the effectiveness of giving women advice to reduce their exposure to trace metals during pregnancy or prior to conception. The study also examined differences in exposure between rural and urban environments in southern France.

Methods

In this prospective study, pregnant women or those intending to conceive were recruited from two medical centers for gynecology/obstetrics (rural location: Saint-Rémy-de-Provence; urban location: Marseille). Hair samples were collected and analyzed to determine the levels of exposure to trace metals. Participants with 'risky' levels were given corresponding advice sheets on how to reduce their exposure or, for certain metals, they were encouraged to find out about potential sources of exposure. A second hair sample was collected and analyzed 3 months later.

Results

It was found that 109 women had 'risky' levels of exposure to trace metals, out of a total of 184 women (59.2 %). Cerium was the most frequently identified metal (N = 26), followed by nickel (N = 23), and titanium (N = 19). There were more women at the urban center with 'risky' levels (56/86; 65.1 %) than at the rural center (53/98; 54.1 %), but this difference was not statistically significant (p = 0.13). Advice sheets were given to 64 of the 109 participants with 'risky' levels (58.7 %), but only 21 returned for the second hair analysis. Of these, 14 were found to have reduced their exposure, which corresponds to just 12.8 % (14/109) of the participants with 'risky' levels.

Conclusions

These results indicate that it would be helpful to develop new interventions to reduce trace metal exposure during or prior to pregnancy.

Cerium oxide nanoparticles in diabetic foot ulcer management: Advances, limitations, and future directions

Diabetic foot ulcer (DFU) is one of the most serious complications of diabetes, potentially resulting in wound infection and amputation under severe circumstances. Oxidative stress and dysbiosis are the primary factors that delay wound healing, posing challenges to effective treatment. Unfortunately, conventional approaches in these aspects have proven satisfactory in achieving curative outcomes. Recent research has increasingly focused on using nanoparticles, leveraging their potential in wound dressing and medication delivery. Their unique physical properties further enhance their therapeutic effectiveness. Among these nanoparticles, cerium oxide nanoparticles (CONPs) have garnered attention due to their notable beneficial effects on oxidative stress and microbial abundance, thus representing a promising therapeutic avenue for DFU. This review comprehensively assesses recent studies on CONPs in treating DFU. Furthermore, we elaborate on the wound healing process, ceria synthesis, and incorporating CONPs with other materials. Crucially, a thorough evaluation of CONPs' toxicity as a novel metallic nanomaterial for therapeutic use must precede their formal clinical application. Additionally, we identify the current challenges CONPs encounter and propose future directions for their development.

Determinants and mechanisms of inorganic nanoparticle translocation across mammalian biological barriers

Biological barriers protect delicate internal tissues from exposures to and interactions with hazardous materials. Primary anatomical barriers prevent external agents from reaching systemic circulation and include the pulmonary, gastrointestinal, and dermal barriers. Secondary barriers include the blood-brain, blood-testis, and placental barriers. The tissues protected by secondary barriers are particularly sensitive to agents in systemic circulation. Neurons of the brain cannot regenerate and therefore must have limited interaction with cytotoxic agents. In the testis, the delicate process of spermatogenesis requires a specific milieu distinct from the blood. The placenta protects the developing fetus from compounds in the maternal circulation that would impair limb or organ development. Many biological barriers are semi-permeable, allowing only materials or chemicals, with a specific set of properties, that easily pass through or between cells. Nanoparticles (particles less than 100 nm) have recently drawn specific concern due to the possibility of biological barrier translocation and contact with distal tissues. Current evidence suggests that nanoparticles translocate across both primary and secondary barriers. It is known that the physicochemical properties of nanoparticles can affect biological interactions, and it has been shown that nanoparticles can breach primary and some secondary barriers. However, the mechanism by which nanoparticles cross biological barriers has yet to be determined. Therefore, the purpose of this review is to summarize how different nanoparticle physicochemical properties interact with biological barriers and barrier products to govern translocation.

Nanotherapeutic potential of antibacterial folic acid-functionalized nanoceria for wound-healing applications

Aim: The functionalization and characterization of antibacterial nanoceria with folic acid (FA) and elucidation of their in vivo wound healing application. Materials & methods: Functionalization of nanoceria were done with FA using a chemical method and their antibacterial activity, cellular biocompatibility and in vivo wound healing application were evaluated. Results: The functionalization of nanoceria with FA was done with 10 to 20 nm size and -20.1 mV zeta potential. The nanoformulation showed a bacteriostatic effect along with biocompatibility to different cell lines; 0.1% w/v spray of FA-nanoceria demonstrated excellent wound healing capacity within 14 days in a Wister rat model. Conclusion: The antioxidant and reactive oxygen species scavenging activity of the FA-nanoceria make it a promising therapeutic agent as a unique spray formulation in wound healing applications.

Skin absorption of inorganic nanoparticles and their toxicity: A review

The role of inorganic nanoparticles in our society is increasing every day, from its use in sunscreens to their introduction in analytical laboratories, pharmacy, medicine, agricultural and other uses. Therefore, in order to establish precautions as well as correct handling of this type of material by operators, it is important to determine the ability of these compounds to travel through the different layers of the skin and to study their possible toxicological effects. In this sense, several authors have studied the ability of inorganic nanoparticles to penetrate the skin barrier by diverse methodologies in in vivo and in vitro modes. In the first case, most of the studies have been performed with animal skins that can imitate the human one (porcine, mouse and guinea pigs, among others), although human skin from surgery have been also explored. However, the use of animals is a common model that should be avoided in the following years due to ethical issues. In this sense, the use of in vitro methodologies is also usually selected to study the dermal absorption of nanoparticles through the skin. Nevertheless, most of the studies are performed with authentic animal skins, instead of the use of synthetic skins that imitate the permeability of our skin system, which has been scarcely studied. In addition, most of the literature is focused in achieving high-transdermal uptake to use nanoparticles (not only inorganic) as carriers for drugs, but little efforts have been done in the study of their inherent percutaneous absorption and toxicity. For these reasons, this review covers the current state-of-the-art of dermal absorption of inorganic nanoparticles in skin and their possible toxicity taking into account that people can be in contact with these nanomaterials in daily life, work or other places. In this sense, the observed results showed that the nanoparticles rarely reach the blood circulatory system, and no big toxicological effects were commonly found when in vivo and actual skin was used. In addition, similar results were found when synthetic skins were used, demonstrating the possibility of avoiding animals in these studies. In any case, more studies covering the dermal absorption of nanoparticles should be performed to have a better understanding of how nanoparticles can affect our health.

Chitosan functionalization of metal- and carbon-based nanomaterials as an approach toward sustainability tomorrow

The growing number of nanomaterials-based-products ranging from agriculture to cosmetics to medical, and so on, increases the amount of exposure, compelling researchers to include safety and health protocols in each developed nano-product to ensure consumer safety. As a result, emphasizing the importance of novel nanomaterials' toxicological and safety profiles, as well as their product quality enhancement, is critical. As a result, research efforts must be directed toward developing new nanomaterials in a safer-by-design manner. Chitosan functionalization is an excellent option for this because it is already known for its nontoxicity, biodegradability, and biocompatibility. In this review, we hope to uncover the toxicological consequences of nanomaterials and the potential role of chitosan functionalization in mitigating them. This is an effort to create an environmentally friendly and safe nano-product, ensuring tomorrow's sustainability.

Experimental and In-Silico Computational Modeling of Cerium Oxide Nanoparticles Functionalized by Gelatin as an Eco-Friendly Anti-Corrosion Barrier on X60 Steel Alloys in Acidic Environments

An eco-friendly and a facile route successfully prepared novel cerium oxide nanoparticles functionalized by gelatin. The introduced CeO₂@gelatin was investigated in terms of FE-SEM, EDX, TEM, chemical mapping, FT-IR, and (TGA) thermal analyses. These characterization tools indicate the successful synthesis of a material having CeO₂ and gelatin as a composite material. The prepared composite CeO₂@gelatin was used as an environment-friendly coated film or X60 steel alloys in acidizing oil well medium. Moreover, the effect of CeO₂ percent on film composition was investigated. LPR corrosion rate, E_ocp-time, EIS, and PDP tools determined the corrosion protection capacity. The CeO₂@gelatin composite exhibited high protection capacity compared to pure gelatin; in particular, 5.0% CeO₂@gelatin coating film shows the highest protection capacity (98.2%), with long-term anti-corrosive features. The % CeO₂@gelatin-coated films formed the protective adsorbed layer on the steel interface by developing a strong bond among nitrogen atoms in the CeO₂@gelatin film and the electrode interface. Surface morphology using FESEM measurements confirmed the high efficiency of the fabricated CeO₂@gelatin composite on the protection X60 steel alloys. DFT calculations and MC simulations were explored to study the relations between the protection action and the molecular construction of the coated systems, which were in good alignment with the empirical findings.

Transdermal permeation of inorganic cerium salts in intact human skin

The stratum corneum protects the body against external agents, such as metals, chemicals, and toxics. Although it is considered poorly permeable to them, comprising the major barrier to the permeation of such substances, it may become a relevant gate of entry for such molecules. Cerium (Ce) is a lanthanide that is widely used in catalytic, energy, biological and medicinal applications, owing to its intrinsic structural and unique redox properties. Cerium salts used to produce cerium oxide (CeO₂) nanostructures can potentially come into contact with the skin and be absorbed following dermal exposure. The objective of this study was to investigate the percutaneous absorption of three inorganic Ce salts: cerium (III) chloride (CeCl₃); cerium (III) nitrate (Ce(NO₃)₃) and ammonium cerium (IV) nitrate (Ce(NH₄)₂(NO₃)₆), which are commonly adopted for the synthesis of CeO₂ using in vitro - ex vivo technique in Franz diffusion cells. The present work shows that Ce salts cannot permeate intact human skin, but they can penetrate significantly in the epidermis (up to 0.29 μg/cm²) and, to a lesser extent in dermis (up to 0.11 μg/cm²). Further studies are required to evaluate the potential effects of long-term exposure to Ce.

The role of size-controlled CeO2 nanoparticles in enhancing the stability and photocatalytic performance of ZnO in natural sunlight exposure

In order to enhance the photocatalytic performance and stability, the various proportions of the size controlled cerium oxide (CeO₂) nanoparticles were dispersed at the pre-synthesized ZnO. Although, the expected dual absorption onsets, probably due to the diminutive difference between the bandgaps of CeO₂ (∼2.9 eV) and ZnO (∼3.1 eV), were not observed however, a blue shift in the bandgap energy of ZnO was witnessed with the increasing surface density of CeO₂ particles. The delayed excitons recombination process with the increasing concentration of CeO₂ nanoparticles was verified by the PL spectra. The structural investigation by Raman and XRD analysis revealed the surface attachment of CeO₂ particles without altering the rock-salt lattice of ZnO. The morphological and fine microstructural analysis established the uniform distribution of evenly sized CeO₂ particles at the surface of ZnO with the discrete fringe patterns of both the entities whereas the XPS analysis confirmed the majority of Ce⁴⁺ in dispersed CeO₂. In comparison to pure ZnO, cyclic voltammetric (CV) analysis, under illumination, exposed the supportive role of surface residing CeO₂ particles in eradicating the photo-corrosion of ZnO whereas the chronopotentiometry (CP) predicted the prolonged life-span of the excitons. Compared to pure ZnO, an appreciably high activity was revealed for 10% CeO₂ loading as compared to pure ZnO for the removal of mono and di-nitrophenol derivatives and their mixtures under natural sunlight exposure. The variations in the removal rates in the mixture as compared to individual nitrophenol exposed the structure-based priority of ROS for the respective phenol. The significantly enhanced photocatalytic activity of the composite catalysts revealed the incremental role of surface-mounted CeO₂ entities in boosting the generation of ROS under sunlight irradiation. The experimental observations were correlated and compiled to establish the mechanism of the removal process.

On Placental Toxicology Studies and Cerium Dioxide Nanoparticles

The human placenta is a transient organ essential for pregnancy maintenance, fetal development and growth. It has several functions, including that of a selective barrier against pathogens and xenobiotics from maternal blood. However, some pollutants can accumulate in the placenta or pass through with possible repercussions on pregnancy outcomes. Cerium dioxide nanoparticles (CeO₂ NPs), also termed nanoceria, are an emerging pollutant whose impact on pregnancy is starting to be defined. CeO₂ NPs are already used in different fields for industrial and commercial applications and have even been proposed for some biomedical applications. Since 2010, nanoceria have been subject to priority monitoring by the Organization for Economic Co-operation and Development in order to assess their toxicity. This review aims to summarize the current methods and models used for toxicology studies on the placental barrier, from the basic ones to the very latest, as well as to overview the most recent knowledge of the impact of CeO₂ NPs on human health, and more specifically during the sensitive window of pregnancy. Further research is needed to highlight the relationship between environmental exposure to CeO₂ and placental dysfunction with its implications for pregnancy outcome.

Nanostructured Ceria: Biomolecular Templates and (Bio)applications

Ceria (CeO2) nanostructures are well-known in catalysis for energy and environmental preservation and remediation. Recently, they have also been gaining momentum for biological applications in virtue of their unique redox properties that make them antioxidant or pro-oxidant, depending on the experimental conditions and ceria nanomorphology. In particular, interest has grown in the use of biotemplates to exert control over ceria morphology and reactivity. However, only a handful of reports exist on the use of specific biomolecules to template ceria nucleation and growth into defined nanostructures. This review focusses on the latest advancements in the area of biomolecular templates for ceria nanostructures and existing opportunities for their (bio)applications.

Salivary Leucocytes as In Vitro Model to Evaluate Nanoparticle-Induced DNA Damage

Metal oxide nanoparticles (NPs) have a wide variety of applications in many consumer products and biomedical practices. As a result, human exposure to these nanomaterials is highly frequent, becoming an issue of concern to public health. Recently, human salivary leucocytes have been proposed as an adequate non-invasive alternative to peripheral blood leucocytes to evaluate genotoxicity in vitro. The present study focused on proving the suitability of salivary leucocytes as a biomatrix in the comet assay for in vitro nanogenotoxicity studies, by testing some of the metal oxide NPs most frequently present in consumer products, namely, titanium dioxide (TiO2), zinc oxide (ZnO), and cerium dioxide (CeO2) NPs. Primary and oxidative DNA damage were evaluated by alkaline and hOGG1-modified comet assay, respectively. Any possible interference of the NPs with the methodological procedure or the hOGG1 activity was addressed before performing genotoxicity evaluation. Results obtained showed an increase of both primary and oxidative damage after NPs treatments. These data support the use of salivary leucocytes as a proper and sensitive biological sample for in vitro nanogenotoxicity studies, and contribute to increase the knowledge on the impact of metal oxide NPs on human health, reinforcing the need for a specific regulation of the nanomaterials use.

Applications of Nanosized-Lipid-Based Drug Delivery Systems in Wound Care

Impaired wound healing is an encumbering public health issue that increases the demand for developing new therapies in order to minimize health costs and enhance treatment efficacy. Available conventional therapies are still unable to maximize their potential in penetrating the skin at the target site and accelerating the healing process. Nanotechnology exhibits an excellent opportunity to enrich currently available medical treatments, enhance standard care and manage wounds. It is a promising approach, able to address issues such as the permeability and bioavailability of drugs with reduced stability or low water solubility. This paper focuses on nanosized-lipid-based drug delivery systems, describing their numerous applications in managing skin wounds. We also highlight the relationship between the physicochemical characteristics of nanosized, lipid-based drug delivery systems and their impact on the wound-healing process. Different types of nanosized-lipid-based drug delivery systems, such as vesicular systems and lipid nanoparticles, demonstrated better applicability and enhanced skin penetration in wound healing therapy compared with conventional treatments. Moreover, an improved chemically and physically stable drug delivery system, with increased drug loading capacity and enhanced bioavailability, has been shown in drugs encapsulated in lipid nanoparticles. Their applications in wound care show potential for overcoming impediments, such as the inadequate bioavailability of active agents with low solubility. Future research in nanosized-lipid-based drug delivery systems will allow the achievement of increased bioavailability and better control of drug release, providing the clinician with more effective therapies for wound care.

Solvothermal Synthesis Routes to Substituted Cerium Dioxide Materials

We review the solution-based synthesis routes to cerium oxide materials where one or more elements are included in place of a proportion of the cerium, i.e., substitution of cerium is performed. The focus is on the solvothermal method, where reagents are heated above the boiling point of the solvent to induce crystallisation directly from the solution. This yields unusual compositions with crystal morphology often on the nanoscale. Chemical elements from all parts of the periodic table are considered, from transition metals to main group elements and the rare earths, including isovalent and aliovalent cations, and surveyed using the literature published in the past ten years. We illustrate the versatility of this synthesis method to allow the formation of functional materials with applications in contemporary applications such as heterogeneous catalysis, electrodes for solid oxide fuel cells, photocatalysis, luminescence and biomedicine. We pick out emerging trends towards control of crystal habit by use of non-aqueous solvents and solution additives and identify challenges still remaining, including in detailed structural characterisation, the understanding of crystallisation mechanisms and the scale-up of synthesis.

A short review of alternative ingredients and technologies of inorganic UV filters

BACKGROUND

The growing need to use sunscreens is a concrete reality, and it is associated with the increase in the population's awareness of the ultraviolet (UV) radiation damage. Inorganic UV filters promote the formation of particles/pigments film over the skin surface, reflecting, dispersing, and absorbing the radiation. Investigations of this class of filters demonstrate the emergence of alternative ingredients and new technologies.

AIMS AND METHODS

In this review, we presented potential candidates for alternative UV inorganic filters, such as hydroxyapatite, cerium dioxide, and hydrotalcite.

RESULTS

Specialized literature identified hydroxyapatite and cerium dioxide as actives with good performances, with a broad spectrum of absorption against UV radiation. Both of them were considered safe against degradation and skin erythema formation. Inorganic compounds as an alternative to circumvent degradation problems of organic UV filters containing PABA were also analyzed, with hydrotalcite having a good performance in improving the performance of classic ingredients, bypassing photoinstability, and improving safety, in addition to preventing skin irritability.

CONCLUSION

Further investigations of these ingredients and interactions with sunscreen formulations are necessary to overall explore their safety and efficacy, encouraging future researches for more inorganic UV filters.

Lipid Nanoparticles as a Skin Wound Healing Drug Delivery System: Discoveries and Advances

Chronic wounds are a remarkable cause of morbidity, requiring long-time treatments with a significant impact on the quality of life and high costs for public health. Although there are a variety of topical skin preparations commercially available, they have several limitations that frequently impair wound healing, such as drug instability, toxicity, limited time of action and ineffective skin permeation. In recent years, researchers have focused on the development of new effective treatments for wound healing and shown frequent interest in nanometric drug delivery systems to overcome such obstacles. In dermatology, lipid nanoparticles (LNPs) have received great attention from researchers due to their great functionalities, greater adhesion to the skin and film formation, enabling the hydration and maintenance of skin integrity, as well as present a more effective penetration through the skin barrier. This review provides an update on topical formulations based on Solid Lipid Nanoparticles (SLNs) and Nanostructured Lipid Carriers (NLCs) as wound healing treatments. Both SLNs and NLCs are able to increase solubility and stability of active pharmaceutical ingredients and increase skin penetration compared to the free drugs. Additionally, SLNs and NLCs can increase pharmacological activity, increase the release profile of the drugs, promote synergistic effects and improve the sensory properties of the final formulation. Topical dosage forms containing nanoparticles have been extensively evaluated for wound healing activity, mainly the dressings, films and scaffolds. Therefore, lipid nanoparticles have contributed in improving wound healing therapies when incorporated into other dosage forms with better efficacy and lesser adverse effects than conventional formulations.