Recent advances in nanomaterial-based optical biosensors for food safety applications: Ochratoxin-A detection, as case study.

Global population growth tremendously impacts the global food industry, endangering food safety and quality. Mycotoxins, particularly Ochratoxin-A (OTA), emerge as a food chain production threat, since it is produced by fungus that contaminates different food species and products. Beyond this, OTA exhibits a possible human toxicological risk that can lead to carcinogenic and neurological diseases. A selective, sensitive, and reliable OTA biodetection approach is essential to ensure food safety. Current detection approaches rely on accurate and time-consuming laboratory techniques performed at the end of the food production process, or lateral-flow technologies that are rapid and on-site, but do not provide quantitative and precise OTA concentration measurements. Nanoengineered optical biosensors arise as an avant-garde solution, providing high sensing performance, and a fast and accurate OTA biodetection screening, which is attractive for the industrial market. This review core presents and discusses the recent advancements in optical OTA biosensing, considering engineered nanomaterials, optical transduction principle and biorecognition methodologies. Finally, the major challenges and future trends are discussed, and current patented OTA optical biosensors are emphasized for a particular promising detection method.

Biosensors Advances: Contributions to Cancer Diagnostics and Treatment.

Cancer is the second leading cause of death worldwide, and its survival rate is significantly affected by early detection and treatment. However, most current diagnostic methods are symptoms oriented, and detecting cancer only in advanced phases. The few existent screening methods, such as mammograms and papanicolaou tests are invasive and not continuous, resulting in a high percentage of non-detected cancers in the early phases. Thus, there is an urgent need to create technologies that make cancer diagnostics more accessible to populations, enabling continuous or semi-continuous, noninvasive, "long-term" screening of cancer in high-risk patients and the whole population. Biosensors are being developed to create technologies that can be applied to point-of-care, wearable, and implantable diagnostics, aiming to fill this important gap in cancer early detection, and, therefore, increase the cancer rate of survival and reduce its morbidity. The versatility of these technologies, due to their miniaturization and diverse detection modes, will enable great advances in cancer early detection, since they can be adapted to the patient and its context, allowing personalized medicine to become a reality.

Hydrogel-Based Strategies to Advance Therapies for Chronic Skin Wounds.

Chronic skin wounds are the leading cause of nontraumatic foot amputations worldwide and present a significant risk of morbidity and mortality due to the lack of efficient therapies. The intrinsic characteristics of hydrogels allow them to benefit cutaneous healing essentially by supporting a moist environment. This property has long been explored in wound management to aid in autolytic debridement. However, chronic wounds require additional therapeutic features that can be provided by a combination of hydrogels with biochemical mediators or cells, promoting faster and better healing. We survey hydrogel-based approaches with potential to improve the healing of chronic wounds by reviewing their effects as observed in preclinical models. Topics covered include strategies to ablate infection and resolve inflammation, the delivery of bioactive agents to accelerate healing, and tissue engineering approaches for skin regeneration. The article concludes by considering the relevance of treating chronic skin wounds using hydrogel-based strategies.

Gene expression changes are associated with severe bone loss and deficient fracture callus formation in rats with complete spinal cord injury.

STUDY DESIGN: Animal study. OBJECTIVES: To investigate the effects of SCI on bone quality and callus formation. SETTING: University and hospital-based research center, Ribeirão Preto Medical School, Brazil. METHODS: Rats sustaining a complete SCI for 10 days received a fracture at the femoral diaphysis and were followed-up for 14 days. Bone callus and contralateral nonfractured tibia were assessed by DXA, µCT, ELISA, histomorphometry, immunohistochemistry, biomechanical test, and gene expression. RESULTS: SCI downregulated osteoblastic-related gene expression in the nonfractured tibias, associated with a twofold increase in osteoclasts and overexpression of RANK/RANKL, which resulted in lower bone mass, impaired microarchitecture, and weaker bones. On day 14 postfracture, we revealed early and increased trabecular formation in the callus of SCI rats, despite a marked 75% decrease in OPG-positive cells, and 41% decrease in density. Furthermore, these calluses showed higher porosity and thinner newly formed trabeculae, leading to lower strength and angle failure. CONCLUSIONS: SCI-induced bone loss resulted from increased bone resorption and decreased bone formation. We also evidenced accelerated bone healing in the SCI rats, which may be attributed to the predominant intramembranous ossification. However, the newly formed bone was thinner, less dense, and more porous than those in the non-SCI rats. As a result, these calluses are weaker and tolerate lesser torsion deformation than the controls, which may result in recurrent fractures and characterizes a remarkable feature that may severely impair life quality.

Microfluidic Devices and Three Dimensional-Printing Strategies for in vitro Models of Bone.

Bone is a complex and highly dynamic tissue, which has been worldwide studied, from fundamental biology to tissue engineering fields. Even so, current in vitro models do not truly replicate the native bone tissue environment. For so, new and improved in vitro tissue models are necessary to obtain more reliable data, not only in a development point of view, but also to fasten the translation of new drugs into the clinics. In this reasoning, tissue-engineering strategies were applied to develop mimetic and three-dimensional (3D) microenvironments, which were associated with microfluidic devices for the development of more complex and realistic systems. Such devices mimic blood vessels that are present in the native tissue, thus enabling the study of complex biological mechanism as such as bone angiogenesis. More recently, 3D printing has been pursued to produce more intricate microfluidic devices and engineered tissues in a single step. The ability to print spatially controlled structures composed of different biomaterials, growth factors and cells caught the attention of scientists for the development of more efficient in vitro models. Additionally, it allows obtaining microfluidic devices and/or engineered tissues with the desired architecture within a small amount of time and with reduced costs. Recently, the use of high-resolution scanning boosted the production of patient-specific implants. Despite the difficulties associated with 3D printed structures that still need to be overcome, it has been proven to be a valuable tool to accomplish a new generation of 3D bioprinted bone-on-a-chip platforms.

Bioceramics for Osteochondral Tissue Engineering and Regeneration.

Considerable advances in tissue engineering and regeneration have been accomplished over the last decade. Bioceramics have been developed to repair, reconstruct, and substitute diseased parts of the body and to promote tissue healing as an alternative to metallic implants. Applications embrace hip, knee, and ligament repair and replacement, maxillofacial reconstruction and augmentation, spinal fusion, bone filler, and repair of periodontal diseases. Bioceramics are well-known for their superior wear resistance, high stiffness, resistance to oxidation, and low coefficient of friction. These specially designed biomaterials are grouped in natural bioceramics (e.g., coral-derived apatites), and synthetic bioceramics, namely bioinert ceramics (e.g., alumina and zirconia), bioactive glasses and glass ceramics, and bioresorbable calcium phosphates-based materials. Physicochemical, mechanical, and biological properties, as well as bioceramics applications in diverse fields of tissue engineering are presented herein. Ongoing clinical trials using bioceramics in osteochondral tissue are also considered. Based on the stringent requirements for clinical applications, prospects for the development of advanced functional bioceramics for tissue engineering are highlighted for the future.

Clinical Trials and Management of Osteochondral Lesions.

Osteochondral lesions are frequent and important causes of pain and disability. These lesions are induced by traumatic injuries or by diseases that affect both the cartilage surface and the subchondral bone. Due to the limited cartilage ability to regenerate and self-repair, these lesions tend to gradually worsen and progress towards osteoarthritis. The clinical, social, and economic impact of the osteochondral lesions is impressive and although therapeutic alternatives are under discussion, a consensus is not yet been achieved. Over the previous decade, new strategies based on innovative tissue engineering approaches have been developed with promising results. However, in order those products reach the market and help the actual patient in an effective manner, there is still a lot of work to be done. The current state of the implications, clinical aspects, and available treatments for this pathology, as well as the ongoing preclinical and clinical trials are presented in this chapter.

The efficient role of sodium alginate-based biodegradable dressings for skin wound healing application: a systematic review.

Injuries and damage to the skin can be caused by different reasons throughout human life. The use of sodium alginate in tissue dressing has been highly studied due to its intrinsic properties, including its degradation rate and biocompatibility, and the capacity of supporting tissue proliferation. The aim of this paper is to demonstrate evidences, through a systematic review method, to support the application of sodium alginate as a curative and as a potential accelerator in the healing of skin wounds. Four databases were used to develop this systematic review: Science Direct, PubMed, Scielo and Scopus. The time interval established for the search was from January 2016 to October 2023. After applying the exclusion and inclusion criteria, each selected article was evaluated and it was observed that the improvement of the mechanical properties of sodium alginate when correctly processed and crosslinked were evident. However, the increase of crosslinking affects as the wettability and the swelling of the biomaterials can cause limitations in mechanical properties and hidrophilic behavior. To achieve the ideal dressing, it is necessary to apply the optimal concentration of crosslinking and other substances, which can damage its hidrophilic characteristic. Thus, it was concluded that sodium alginate has every caracteristic desirable to develop an effective and safe dressing.

Natural melanin nanoparticles (MNPs) extracted from Sepia officinalis: A cost-effective, chemo-photothermal, synergistic nanoplatform for osteosarcoma treatment.

Osteosarcoma conventional chemotherapeutics are known for their side effects, limited options, and induction of drug resistance. This creates the need to develop new therapeutics capable of effectively destroying cancer cells with low toxicity, improving patient survival rate and their life quality. This work reports a novel drug delivery nanoplataform made of Natural Melanin Nanoparticles (MNPs), obtained from Sepia officinalis ink, with 99% incorporation efficiency of doxorubicin (Dox) without the use of non-toxic solvents. A significant photothermal effect was shown by a 36ºC increment after 10 min of laser irradiation, surpassing reported values for synthetic melanin. A sustained drug release of ca. 23% with photothermal stimuli was observed, compared to 15% without stimuli, after 48 h. This nanoplatform is obtained as a food industry side product, which makes it a natural cost-effective biomedical material. Natural MPs were applied in an osteosarcoma cell line (SaOs-2), and internalized by the cells in less than 2 h, showing cytocompatibility up to 1000 µg/mL after 72 h of contact with cells. On the contrary, when natural MNPs loaded with Dox (Dox-MNPs) were placed in contact with the SaOs-2 cells and were simultaneously receiving NIR light it was observed a 93% reduction in cancer cells in 48 h, revealing a synergistic effect between chemotherapy and phototherapy. To our knowledge this is the first time that natural MNPs extracted from Sepia officinalis were tested on an osteosarcoma cell line as chemo-photothermal agent, showing these NPs are an effective, cost-effective, reproducible, non-toxic nanoplatform for osteosarcoma treatment using combined effects.

Hydroxyapatite/alginate/gellan gum inks with osteoconduction and osteogenic potential for bioprinting bone tissue analogues.

There is a growing demand for engineered bone tissues custom-designed to match the patient-specific defect size and in vitro models for studying bone diseases and/or drug screening. Herein, we propose a bioprinted bone tissue construct using SaOs-2 cells within alginate/gellan gum/hydroxyapatite inks. Different ink formulations were developed with varying hydroxyapatite content and then evaluated for viscoelasticity, printability, biomineralization properties, post-printing viability, proliferation, metabolic activity, and osteogenic phenotype of SaOs-2-encapsulated cells. Results indicate that ink formulations exhibit non-Newtonian shear-thinning behaviour, maintaining shape integrity and structural stability post-printing. Ink mineralization rates increase with the hydroxyapatite content, rendering them suitable for bone defect strategies. Post-printed cells in the developed constructs remain live, spreading, and metabolically active but do not proliferate. Osteogenic gene and protein expression, both early and late, show upregulation at day 7 relative to day 1, followed by downregulation at day 14. Lower hydroxyapatite content inks demonstrate up to fourfold upregulation in genes and proteins at most time points. Additionally, these constructs release calcium and phosphate at levels conducive to mineralization. Overall, the tissue-engineered miniaturized constructs not only meet the criteria for early-stage bone defect/fracture regeneration but also serve as a promising platform for drug screening and evaluating potential therapeutic treatments.

Migration of "bioabsorbable" screws in ACL repair. How much do we know? A systematic review.

PURPOSE: Although bioabsorbable screws promise to degrade within months up to several years after implantation, often this does not happen. In fact, other problems such as screw breakage, tunnel enlargement, allergic or foreign body reactions, cyst or abscess formation, and delayed migration of "biodegradable" screws have been reported. This study aims to provide relevant basic science knowledge and recent insights concerning "biomaterials" currently used in fixation devices for anterior cruciate ligament (ACL) repair. A systematic review on the topic of screw "migration" is provided. METHODS: A PubMed search combining all the key terms was done looking for complications related to late migration of "bioabsorbable" screws used in ACL reconstruction without inferior time limitation up to January 2012. Only clinical reports were included. Reference lists of reports were checked to detect others not identified by the original search. A pre-publication search was performed to identify the most recent relevant articles. RESULTS: A total of ten articles referred to migration of "bioabsorbable" interference screws. Most cases reported on poly-L-lactic acid-based screws. Migration was noticed between 3 and 22 months postoperatively. It was noticed both in the tibia and the femur and with the application of several types of graft. CONCLUSION: Migration is a possible complication of "bioabsorbable" interference screws. The information related to all clinical implications of the so-called "biodegradable screws" remains scarce and probably suffers from the phenomenon of publication bias. The complexity of possible reactions occurring in the human body is difficult to reproduce under controlled laboratory conditions.

Preclinical research studies for treating severe muscular injuries: focus on tissue-engineered strategies.

Severe skeletal muscle injuries are a lifelong trauma with limited medical solutions. Significant progress has been made in developing in vitro surrogates for treating such trauma. However, more attention is needed when translating these approaches to the clinic. In this review, we survey the potential of tissue-engineered surrogates in promoting muscle healing, by critically analyzing data from recent preclinical models. The therapeutic advantages provided by a combination of different biomaterials, cell types, and biochemical mediators are discussed. Current therapies on muscle healing are also summarized, emphasizing their main advantages and drawbacks. We also discuss previous and ongoing clinical trials as well as highlighting future directions for the field.

Human adipose-derived mesenchymal stem cells laden in gellan gum spongy-like hydrogels for volumetric muscle loss treatment.

BACKGROUND: volumetric muscle loss (VML) is a traumatic massive loss of muscular tissue which frequently leads to amputation, limb loss, or lifetime disability. The current medical intervention is limited to autologous tissue transfer, which usually leads to non-functional tissue recovery. Tissue engineering holds a huge promise for functional recovery. METHODS: in this work, we evaluated the potential of human adipose-derived mesenchymal stem cells (hASCs) pre-cultured in gellan gum based spongy-like hydrogels (SLHs). RESULTS: in vitro, hASCs were spreading, proliferating, and releasing growth factors and cytokines (i.e. fibroblast growth factor, hepatocyte growth factor, insulin-like growth factor 1, interleukin-6 (IL-6), IL-8, IL-10, vascular endothelial growth factor) important for muscular regeneration. After implantation into a volumetric muscle loss (VML) mouse model, implants were degrading overtime, entirely integrating into the host between 4 and 8 weeks. In both SLH and SLH + hASCs defects, infiltrated cells were observed inside constructs associated with matrix deposition. Also, minimal collagen deposition was marginally observed around the constructs along both time-points. Neovascularization (CD31+vessels) and neoinnervation (ß-III tubulin+bundles) were significantly detected in the SLH + hASCs group, in relation to the SHAM (empty lesion). A higher density ofα-SA+and MYH7+cells were found in the injury site among all different experimental groups, at both time-points, in relation to the SHAM. The levels ofα-SA, MyoD1, and myosin heavy chain proteins were moderately increased in the SLH + hASCs group after 4 weeks, and in the hASCs group after 8 weeks, in relation to the SHAM. CONCLUSIONS: taken together, defects treated with hASCs-laden SLH promoted angiogenesis, neoinnervation, and the expression of myogenic proteins.

Collagen membrane from bovine pericardium for treatment of long bone defect.

The treatment of bone regeneration failures has been constantly improved with the study of new biomaterials. Techgraft® is a collagen membrane derived from bovine pericardium, which has been shown to have biocompatibility and effectiveness in tissue repair. However, its use in orthopedics has not yet been evaluated. Therefore, the purpose of this study was to characterize a bovine pericardium collagen membrane and evaluate the effects of its use in the regeneration of a bone defect in rat tibia. Scanning electron microscopy, atomic force microscopy, weight lost and water uptake tests, and mechanical test were performed. Afterwards, the membrane was tested in an experimental study, using 12 male Sprague Dawley rats. A bone defect was surgically made in tibiae of animals, which were assigned to two groups (n = 6): bone defect treated with collagen membrane (TG) and bone defect without treatment (CONT). Then, tibiae were submitted to micro-CT. The membranes preserved their natural collagen characteristics, presenting great strength, high water absorption, hydrophilicity, and almost complete dissolution in 30 days. In the experimental study, the membrane enhanced the growth of bone tissue in contact with its surface. A higher bone volume and trabeculae number and less trabecular space was observed in bone defects of the membrane group compared to the control group at 21 days. In conclusion, the Techgraft membrane seems to have favorable characteristics for treatment of long bone repair.

Inconsistency in Shoulder Arthrometers for Measuring Glenohumeral Joint Laxity: A Systematic Review.

There is no consensus on how to measure shoulder joint laxity and results reported in the literature are not well systematized for the available shoulder arthrometer devices. This systematic review aims to summarize the results of currently available shoulder arthrometers for measuring glenohumeral laxity in individuals with healthy or injured shoulders. Searches were conducted on the PubMed, EMBASE, and Web of Science databases to identify studies that measure glenohumeral laxity with arthrometer-assisted assessment. The mean and standard deviations of the laxity measurement from each study were compared based on the type of population and arthrometer used. Data were organized according to the testing characteristics. A total of 23 studies were included and comprised 1162 shoulders. Populations were divided into 401 healthy individuals, 278 athletes with asymptomatic shoulder, and 134 individuals with symptomatic shoulder. Sensors were the most used method for measuring glenohumeral laxity and stiffness. Most arthrometers applied an external force to the humeral head or superior humerus by a manual-assisted mechanism. Glenohumeral laxity and stiffness were mostly assessed in the sagittal plane. There is substantial heterogeneity in glenohumeral laxity values that is mostly related to the arthrometer used and the testing conditions. This variability can lead to inconsistent results and influence the diagnosis and treatment decision-making.

In Vitro Cancer Models: A Closer Look at Limitations on Translation.

In vitro cancer models are envisioned as high-throughput screening platforms for potential new therapeutic discovery and/or validation. They also serve as tools to achieve personalized treatment strategies or real-time monitoring of disease propagation, providing effective treatments to patients. To battle the fatality of metastatic cancers, the development and commercialization of predictive and robust preclinical in vitro cancer models are of urgent need. In the past decades, the translation of cancer research from 2D to 3D platforms and the development of diverse in vitro cancer models have been well elaborated in an enormous number of reviews. However, the meagre clinical success rate of cancer therapeutics urges the critical introspection of currently available preclinical platforms, including patents, to hasten the development of precision medicine and commercialization of in vitro cancer models. Hence, the present article critically reflects the difficulty of translating cancer therapeutics from discovery to adoption and commercialization in the light of in vitro cancer models as predictive tools. The state of the art of in vitro cancer models is discussed first, followed by identifying the limitations of bench-to-bedside transition. This review tries to establish compatibility between the current findings and obstacles and indicates future directions to accelerate the market penetration, considering the niche market.

Recent approaches towards bone tissue engineering.

Bone tissue engineering approaches have evolved towards addressing the challenges of tissue mimetic requirements over the years. Different strategies have been combining scaffolds, cells, and biologically active cues using a wide range of fabrication techniques, envisioning the mimicry of bone tissue. On the one hand, biomimetic scaffold-based strategies have been pursuing different biomaterials to produce scaffolds, combining with diverse and innovative fabrication strategies to mimic bone tissue better, surpassing bone grafts. On the other hand, biomimetic scaffold-free approaches mainly foresee replicating endochondral ossification, replacing hyaline cartilage with new bone. Finally, since bone tissue is highly vascularized, new strategies focused on developing pre-vascularized scaffolds or pre-vascularized cellular aggregates have been a motif of study. The recent biomimetic scaffold-based and scaffold-free approaches in bone tissue engineering, focusing on materials and fabrication methods used, are overviewed herein. The biomimetic vascularized approaches are also discussed, namely the development of pre-vascularized scaffolds and pre-vascularized cellular aggregates.

3D bioprinting of gellan gum-based hydrogels tethered with laminin-derived peptides for improved cellular behavior.

The treatment of skeletal muscle defects is still a topic of noteworthy concern since surgical intervention is not capable of recovering muscle function. Herein, we propose myoblasts laden in laminin-inspired biofunctionalized gellan gum hydrogels as promising tissue-engineered skeletal muscle surrogates. Gellan gum-based hydrogels were developed by combining native gellan gum (GG) and GG tethered with laminin-derived peptides (CIKVAVS (V), KNRLTIELEVRTC (T) or RKRLQVQLSIRTC (Q)), using different polymer content (0.75%-1.875%). Hydrogels were characterized in terms of compressive modulus, molecules trafficking, and C2C12 adhesion. Hydrogels with higher polymeric content (1.125%-1.875%) showed higher stiffness whereas hydrogels with lower polymer content (0.75%-1.125%) showed higher fluorescein isothiocyanate-dextran molecules diffusion. Cell spreading was achieved regardless of the laminin-derived peptide but preferred in hydrogels with higher polymer content (1.125%-1.875%). Taken together, hydrogels with 1.125% of polymer content were selected for printability analysis. GG-based inks showed a non-newtonian, shear-thinning, and thixotropic behavior suitable for printing. Accordingly, all inks were printable, but inks tethered with T and Q peptides presented some signs of clogging. Cell viability was affected after printing but increased after 7 days of culture. After 7 days, cells were spreading but not showing significant signs of cell-cell communications. Therefore, cell density was increased, thus, myocytes loaded in V-tethered GG-based inks showed higher cell-cell communication, spreading morphology, and alignment 7, 14 days post-printing. Overall, myoblasts laden in laminin-inspired biofunctionalized GG-based hydrogels are a promising skeletal muscle surrogate with the potential to be used as in vitro model or explored for further in vivo applications.

Injectable laminin-biofunctionalized gellan gum hydrogels loaded with myoblasts for skeletal muscle regeneration.

Moderate muscular injuries that exceed muscular tissue's auto-healing capacity are still a topic of noteworthy concern. Tissue engineering appeared as a promising therapeutic strategy capable of overcoming this unmet clinical need. To attain such goal, herein we propose an in situ-crosslinking gellan gum (GG)-based hydrogel tethered with a skeletal muscle-inspired laminin-derived peptide RKRLQVQLSIRTC(Q) and encapsulated with skeletal muscle cells (SMCs). Pre-hydrogel solutions presented decreasing shear viscosity with increasing shear rate and shear stress, and required low forces for extrusion, validating their injectability. The GGDVS hydrogel was functionalized with Q-peptide with 30% of efficiency. C2C12 were able to adhere to the developed hydrogel, remained living and spreading 7 days post-encapsulation. Q-peptide release studies indicated that 25% of the unbound peptide can be released from the hydrogels up to 7 days, dependent on the hydrogel formulation. Treatment of a chemically-induced muscular lesion in mice with an injection of C2C12-laden hydrogels improved myogenesis, primarily promoted by the C2C12. In accordance, a high density of myoblasts (α-SA+ and MYH7+) were localized in tissues treated with the C2C12 (alone or encapsulated in the hydrogel). α-SA protein levels were significantly increased 8 weeks post-treatment with C2C12-laden hydrogels and MHC protein levels were increased in all experimental groups 4 weeks post-treatment, in relation to the SHAM. Neovascularization and neoinnervation was also detected in the defects. Altogether, this study indicates that C2C12-laden hydrogels hold great potential for skeletal muscle regeneration. STATEMENT OF SIGNIFICANCE: We developed an injectable gellan gum-based hydrogel for delivering C2C12 into localized myopathic model. The gellan gum was biofunctinalized with laminin-derived peptide to mimic the native muscular ECM. In addition, hydrogel was physically tuned to mimic the mechanical properties of native tissue. To the best of our knowledge, this formula was used for the first time under the context of skeletal muscle tissue regeneration. The injectability of the developed hydrogel provided non-invasive administration method, combined with a reliable microenvironment that can host C2C12 with nominal inflammation, indicated by the survival and adhesion of encapsulated cells post-injection. The treatment of skeletal muscle defect with the cell-laden hydrogel approach significantly enhanced the regeneration of localized muscular trauma.

Chitosan Micro-Membranes with Integrated Gold Nanoparticles as an LSPR-Based Sensing Platform.

Currently, there is an increasing need to develop highly sensitive plasmonic sensors able to provide good biocompatibility, flexibility, and optical stability to detect low levels of analytes in biological media. In this study, gold nanoparticles (Au NPs) were dispersed into chitosan membranes by spin coating. It has been demonstrated that these membranes are particularly stable and can be successfully employed as versatile plasmonic platforms for molecular sensing. The optical response of the chitosan/Au NPs interfaces and their capability to sense the medium's refractive index (RI) changes, either in a liquid or gas media, were investigated by high-resolution localized surface plasmon resonance (HR-LSPR) spectroscopy, as a proof of concept for biosensing applications. The results revealed that the lowest polymer concentration (chitosan (0.5%)/Au-NPs membrane) presented the most suitable plasmonic response. An LSPR band redshift was observed as the RI of the surrounding media was incremented, resulting in a sensitivity value of 28 ± 1 nm/RIU. Furthermore, the plasmonic membrane showed an outstanding performance when tested in gaseous atmospheres, being capable of distinguishing inert gases with only a 10-5 RI unit difference. The potential of chitosan/Au-NPs membranes was confirmed for application in LSPR-based sensing applications, despite the fact that further materials optimization should be performed to enhance sensitivity.