General Muscle Torque Generator Model for a Two Degree-of-Freedom Shoulder Joint.

Muscle torque generators (MTGs) have been developed as an alternative to muscle-force models, reducing the muscle-force model complexity to a single torque at the joint. Current MTGs can only be applied to single Degree-of-freedom (DoF) joints, leading to complications in modeling joints with multiple-DoFs such as the shoulder. This study aimed to develop an MTG model that accounts for the coupling between 2-DoF at the shoulder joint: shoulder plane of elevation (horizontal abduction/adduction) and shoulder elevation (flexion/extension). Three different 2-DoF MTG equations were developed to model the coupling between these two movements. Net joint torques at the shoulder were determined for 20 participants (10 females and 10 males) in isometric, isokinetic, and passive tests. Curve and surface polynomial fitting were used to find the best general fit for the experimental data in terms of the different degrees of coupling. The models were validated against experimental isokinetic torque data. It was determined that implicit coupling that used interpolation between single-DoF MTGs resulted in the lowest root-mean-square percent error of 8.5%. The work demonstrated that general MTG models can predict torque results that are dependent on multiple-DoFs of the shoulder.

Gamma irradiation and ozone application as preservation methods for longer-term storage of bee pollen.

Bee pollen is a healthy product with a good nutritional profile and therapeutic properties. Its high moisture content, however, promotes the growth of bacteria, molds, and yeast during storage commonly result in product degradation. Therefore, the aim of this study is to assess the effectiveness of gamma irradiation (GI) and ozone (OZ) as bee pollen preservation methods for longer storage time, as well as whether they are influenced by pollen species. To do that, GI at a dosage of 2.5, 5.0, and 7.5 kGy was applied at a rate of 0.68 kGy/h and OZ application at a concentration of 0.01, 0.02, and 0.03 g/m3 was applied for one time for 6 h, to Egyptian clover and maize bee pollen, then stored at ambient temperature for 6 months. We then determined the total phenolic content (TPC) and antioxidant activity of treated and non-treated pollen samples at 0, 3, and 6 months of storage. Total bacteria, mold, and yeast count were also evaluated at 0, 2, 4, and 6 months. Statistical analyses revealed that, TPC, antioxidant, and microbial load of both clover and maize pollen samples were significantly (p < 0.05) affected by both treatment and storage time and their interaction. Both methods were extremely effective at preserving the antioxidant properties of pollen samples after 6 months of storage at room temperature. Furthermore, the highest concentrations of both GI and OZ applications completely protected pollen samples from mold and yeast while decreasing bacterial contamination. GI at the highest dose (7.5 KGy) was found to be more effective than other GI doses and OZ application in preserving biologically active compounds and lowering the microbial count of pollen samples for 6 months. As a result, we advise beekeepers to use GI at this dose for longer-term storage.

Scalable musculoskeletal model for dynamic simulations of lower body movement.

A musculoskeletal (MSK) model is an important tool for analysing human motions, calculating joint torques during movement, enhancing sports activity, and developing exoskeletons and prostheses. To enable biomechanical investigation of human motion, this work presents an open-source lower body MSK model. The MSK model of the lower body consists of 7 body segments (pelvis, left/right thigh, left/right leg, and left/right foot). The model has 20 degrees of freedom (DoFs) and 28 muscle torque generators (MTGs), which are developed from experimental data. The model can be modified for different anthropometric measurements and subject body characteristics, including sex, age, body mass, height, physical activity, and skin temperature. The model is validated by simulating the torque within the range of motion (ROM) of isolated movements; all simulation findings exhibit a good level of agreement with the literature.

Scalable musculoskeletal model for dynamic simulations of upper body movement.

A musculoskeletal (MSK) model is a valuable tool for assessing complex biomechanical problems, estimating joint torques during motion, optimizing motion in sports, and designing exoskeletons and prostheses. This study proposes an open-source upper body MSK model that supports biomechanical analysis of human motion. The MSK model of the upper body consists of 8 body segments (torso, head, left/right upper arm, left/right forearm, and left/right hand). The model has 20 degrees of freedom (DoFs) and 40 muscle torque generators (MTGs), which are constructed using experimental data. The model is adjustable for different anthropometric measurements and subject body characteristics: sex, age, body mass, height, dominant side, and physical activity. Joint limits are modeled using experimental dynamometer data within the proposed multi-DoF MTG model. The model equations are verified by simulating the joint range of motion (ROM) and torque; all simulation results have a good agreement with previously published research.

Silver nanoparticles formulation of Marrubium alysson L. phenolic extract potentiates cytotoxicity through apoptosis with molecular docking study as Bcl-2 inhibitors.

Crude or semi-purified extracts of plants can play a significant role as antitumor agents. They were used as stabilizing and reducing agents in the preparation of silver nanoparticles (AgNPs) that allows these particles to have more efficient cytotoxic activity. In the current study, the extract of Marrubium alysson L., a plant of common occurrence in Egypt was used to synthesize AgNPs for the first time, where comparison of anticancer activity of crude and phenolic extracts with the AgNPs were extensively studied against cancer cell lines PC-3 and HCT-116. Interestingly, AgNPs of the crude extract exhibited promising cytotoxicity with IC50 values of 10.4 and 16.3 µg/ml, while AgNPs of the phenolic extract exhibited very potent cytotoxicity with IC50 values of 2.66 and 1.34 µg/ml compared to Doxorubicin (as a standard reference drug) that exhibited IC50 values of 5.13 and 4.36 µg/ml, respectively against the tested cells. Additionally, AgNPs of the phenolic extract induced apoptosis in HCT-116 with a higher ratio than in PC-3 cells. It induced apoptosis in PC-3 cells by 79.3-fold change, while it induced total colon apoptotic cell death by 228.3-fold change compared to untreated control. Finally, the apoptotic activity of AgNPs of the phenolic extract in the treated PC-3 and HCT-116 cells was confirmed using RT-PCR. As a result, AgNPs of the phenolic extract could be considered a promising anticancer candidate through apoptosis-induction.Communicated by Ramaswamy H. Sarma.

Therapeutic potential and protection enhancement of mesenchymal stem cell against cisplatin-induced nephrotoxicity using hyaluronic acid-chitosan nanoparticles as an adjuvant.

A newly synthesized nanoplatform of hyaluronic acid and chitosan nanoparticles (HA/CNPs) was applied to improve the therapeutic efficacy and protection of bone marrow mesenchymal stem cells (BM-MSCs) against cisplatin (CDDP)-induced nephrotoxicity in rats. CDDP administration causes significant increases in levels of serum creatinine (SCr), urea, and KIM-1 coupled with significant albumin level falls, as indicative of acute renal dysfunction. Moreover, the level of the antioxidant enzyme (GSH) was significantly decreased, while the levels of lipid peroxidation (MDA) and inflammatory (IL-6) and apoptotic (caspase-3) markers were significantly increased, indicating a decline in the kidney's antioxidant defense and increased inflammation. In contrast, when rats were pre-treated with either MSCs or MSCs-HA/CNPs before receiving CDDP, the levels of SCr, urea, KIM-1, MDA, IL-6, and caspase-3 were significantly decreased with simultaneous significant rises in GSH and albumin, impelling a great improvement in the antioxidant and anti-inflammatory defenses of the kidney as well as its functions. Intriguingly, MSCs-HA/CNPs were more effective against caspase-3 than MSCs alone, revealing the high anti-apoptotic capability of HA/CNPs. This finding suggests that HA/CNPs could effectively protect MSCs from oxidative stress and apoptosis and thus increase their stability and longevity.

Development, Optimization, and In Vitro/In Vivo Evaluation of Azelaic Acid Transethosomal Gel for Antidermatophyte Activity.

Treatment of dermatophytosis is quite challenging. This work aims to investigate the antidermatophyte action of Azelaic acid (AzA) and evaluate its efficacy upon entrapment into transethosomes (TEs) and incorporation into a gel to enhance its application. Optimization of formulation variables of TEs was carried out after preparation using the thin film hydration technique. The antidermatophyte activity of AzA-TEs was first evaluated in vitro. In addition, two guinea pig infection models with Trichophyton (T.) mentagrophytes and Microsporum (M.) canis were established for the in vivo assessment. The optimized formula showed a mean particle size of 219.8 ± 4.7 nm and a zeta potential of -36.5 ± 0.73 mV, while the entrapment efficiency value was 81.9 ± 1.4%. Moreover, the ex vivo permeation study showed enhanced skin penetration for the AzA-TEs (3056 µg/cm2) compared to the free AzA (590 µg/cm2) after 48 h. AzA-TEs induced a greater inhibition in vitro on the tested dermatophyte species than free AzA (MIC90 was 0.01% vs. 0.32% for T. rubrum and 0.032% for T. mentagrophytes and M. canis vs. 0.56%). The mycological cure rate was improved in all treated groups, specially for our optimized AzA-TEs formula in the T. mentagrophytes model, in which it reached 83% in this treated group, while it was 66.76% in the itraconazole and free AzA treated groups. Significant (p < 0.05) lower scores of erythema, scales, and alopecia were observed in the treated groups in comparison with the untreated control and plain groups. In essence, the TEs could be a promising carrier for AzA delivery into deeper skin layers with enhanced antidermatophyte activity.

Experimental Study of Fully Passive, Fully Active, and Active-Passive Upper-Limb Exoskeleton Efficiency: An Assessment of Lifting Tasks.

Recently, robotic exoskeletons are gaining attention for assisting industrial workers. The exoskeleton power source ranges from fully passive (FP) to fully active (FA), or a mixture of both. The objective of this experimental study was to assess the efficiency of a new active-passive (AP) shoulder exoskeleton using statistical analyses of 11 quantitative measures from surface electromyography (sEMG) and kinematic data and a user survey for weight lifting tasks. Two groups of females and males lifted heavy kettlebells, while a shoulder exoskeleton helped them in modes of fully passive (FP), fully active (FA), and active-passive (AP). The AP exoskeleton outperformed the FP and FA exoskeletons because the participants could hold the weighted object for nearly twice as long before fatigue occurred. Future developments should concentrate on developing sex-specific controllers as well as on better-fitting wearable devices for women.

Evaluation of a machine-learning-driven active-passive upper-limb exoskeleton robot: Experimental human-in-the-loop study.

Evaluating exoskeleton actuation methods and designing an effective controller for these exoskeletons are both challenging and time-consuming tasks. This is largely due to the complicated human-robot interactions, the selection of sensors and actuators, electrical/command connection issues, and communication delays. In this research, a test framework for evaluating a new active-passive shoulder exoskeleton was developed, and a surface electromyography (sEMG)-based human-robot cooperative control method was created to execute the wearer's movement intentions. The hierarchical control used sEMG-based intention estimation, mid-level strength regulation, and low-level actuator control. It was then applied to shoulder joint elevation experiments to verify the exoskeleton controller's effectiveness. The active-passive assistance was compared with fully passive and fully active exoskeleton control using the following criteria: (1) post-test survey, (2) load tolerance duration, and (3) computed human torque, power, and metabolic energy expenditure using sEMG signals and inverse dynamic simulation. The experimental outcomes showed that active-passive exoskeletons required less muscular activation torque (50%) from the user and reduced fatigue duration indicators by a factor of 3, compared to fully passive ones.

Comparative Cytotoxic Evaluation of Zygophyllum album Root and Aerial Parts of Different Extracts and Their Biosynthesized Silver Nanoparticles on Lung A549 and Prostate PC-3 Cancer Cell Lines.

The current work demonstrates a comparative study between aerial and root parts of Zygophyllum album L. The total phenolic (TPC) and flavonoid content (TFC), in addition to the antioxidant activity, of the crude extracts were investigated, where the aerial parts revealed a higher value overall. By means of UV-VIS and HPLC, rutin and caffeic acid were detected and then quantified as 5.91 and 0.97 mg/g of the plant extract, respectively. Moreover, the biosynthesis of AgNPs utilizing the crude extract of the arial parts and root of Z. album L. and the phenolic extracts was achieved in an attempt to enhance the cytotoxicity of the different plant extracts. The prepared AgNPs formulations were characterized by TEM and zeta potential measurements, which revealed that all of the formulated AgNPs were of a small particle diameter and were highly stable. The mean hydrodynamic particle size ranged from 67.11 to 80.04 nm, while the zeta potential ranged from 29.1 to 38.6 mV. Upon biosynthesis of the AgNPs using the extracts, the cytotoxicity of the tested samples was improved, so the polyphenolics AgNPs of the aerial parts exhibited a potent cytotoxicity against lung A549 and prostate PC-3 cancer cells with IC50 values of 6.1 and 4.36 µg/mL, respectively, compared with Doxorubicin (IC50 values of 6.19 and 5.13 µg/mL, respectively). Regarding the apoptotic activity, polyphenolics AgNPs of the aerial parts induced apoptotic cell death by 4.2-fold in PC-3 and 4.7-fold in A549 cells compared with the untreated control. The mechanism of apoptosis in both cancerous cells appeared to be via the upregulation proapoptotic genes; p53, Bax, caspase 3, 8, and 9, and the downregulation of antiapoptotic gene, Bcl-2. Hence, this formula may serve as a good source for anticancer agents against PC-3 and A549 cells.

Design, Formulation, and Characterization of Valsartan Nanoethosomes for Improving Their Bioavailability.

The objective of this study was to formulate and evaluate valsartan (VLT) ethosomes to prepare an optimized formula of VLT-entrapped ethosomes that could be incorporated into a sustained release transdermal gel dosage form. The formulation of the prepared ethosomal gel was investigated and subjected to in vitro drug release studies, ex vivo test, and in vivo studies to assess the effectiveness of ethosomal formulation in enhancing the bioavailability of VLT as a poorly soluble drug and in controlling its release from the transdermal gel dosage form. The acquired results are as follows: Dependent responses were particle size, polydispersity index, zeta potential, and entrapment efficiency. The optimized VLT-ETHs had a nanometric diameter (45.8 ± 0.5 nm), a negative surface charge (-51.4 ± 6.3 mV), and a high drug encapsulation (94.24 ± 0.2). The prepared VLT ethosomal gel (VLT-ethogel) showed a high peak plasma concentration and enhanced bioavailability in rats compared with the oral solution of valsartan presented in the higher AUC (0-∞). The AUC (0-∞) with oral treatment was 7.0 ± 2.94 (µg.h/mL), but the AUC (0-∞) with topical application of the VAL nanoethosomal gel was 137.2 ± 49.88 (µg.h/mL), providing the sustained release pattern of VLT from the tested ethosomal gel.

Silver Nanoparticles Formulation of Flower Head's Polyphenols of Cynara scolymus L.: A Promising Candidate against Prostate (PC-3) Cancer Cell Line through Apoptosis Activation.

Cynara scolymus L. (Family: Compositae) or artichoke is a nutritious edible plant widely used for its hepatoprotective effect. Crude extracts of flower, bract, and stem were prepared and evaluated for their in vitro antioxidant activity and phenolic content. The flower crude extract exhibited the highest phenolic content (74.29 mg GAE/gm) as well as the best in vitro antioxidant activity using total antioxidant capacity (TAC), ferric reducing antioxidant power (FEAP), and 1,1-diphenyl-2-picrylhyazyl (DPPH) scavenging assays compared with ascorbic acid. Phenolic fractions of the crude extracts of different parts were separated and identified using high-performance liquid chromatography HPLC-DAD analysis. The silver nanoparticles of these phenolic fractions were established and tested for their cytotoxicity and apoptotic activity. Results showed that silver nanoparticles of a polyphenolic fraction of flower extract (Nano-TP/Flowers) exhibited potent cytotoxicity against prostate (PC-3) and lung (A549) cancer cell lines with IC50 values of 0.85 µg/mL and 0.94 µg/mL, respectively, compared with doxorubicin as a standard. For apoptosis-induction, Nano-TP/Flowers exhibited apoptosis in PC-3 with a higher ratio than in A549 cells. It induced total prostate apoptotic cell death by 227-fold change while it induced apoptosis in A549 cells by 15.6-fold change. Nano-TP/Flowers upregulated both pro-apoptotic markers and downregulated the antiapoptotic genes using RT-PCR. Hence, this extract may serve as a promising source for anti-prostate cancer candidates.

Comparative Estimation of the Cytotoxic Activity of Different Parts of Cynara scolymus L.: Crude Extracts versus Green Synthesized Silver Nanoparticles with Apoptotic Investigation.

Different parts of Cynara scolymus L. and their green synthesized eco-friendly silver nanoparticles (AgNPs) were screened for their cytotoxicity and apoptotic activity. Results showed that flower extract AgNPs exhibited more potent cytotoxicity compared to the normal form against PC-3 and A549 cell lines with IC50 values of 2.47 µg/mL and 1.35 µg/mL, respectively. The results were compared to doxorubicin (IC50 = 5.13 and 6.19 µg/mL, respectively). For apoptosis-induction, AgNPs prepared from the flower extract induced cell death by apoptosis by 41.34-fold change and induced necrotic cell death by 10.2-fold. Additionally, they induced total prostate apoptotic cell death by a 16.18-fold change, and it slightly induced necrotic cell death by 2.7-fold. Hence, green synthesized flower extract AgNPs exhibited cytotoxicity in A549 and PC-3 through apoptosis-induction in both cells. Consequently, synthesized AgNPs were further tested for apoptosis and increased gene and protein expression of pro-apoptotic markers while decreasing expression of anti-apoptotic genes. As a result, this formula may serve as a promising source for anti-cancer candidates. Finally, liquid chromatography combined with electrospray mass spectrometry (LC-ESI-MS) analysis was assessed to identify the common bioactive metabolites in crude extracts of stem, flower, and bract.

Histopathological examination of cases with acute appendicitis, A retrospective study at King Abdulaziz University Hospital, Jeddah, Saudi Arabia.

Introduction: Appendicitis is one of the most prevalent abdominal emergencies globally. Despite the fact that acute appendicitis is a clinical diagnosis, preoperative imaging investigations are often conducted. Other disorders that might mimic acute appendicitis can occur in the appendix. The aim of this paper is to describe the histopathological findings of all appendectomy specimens. Methods: A retrospective study of 940 cases of appendectomy that were performed between 2010 and 2017 at King Abdulaziz University Hospital, Jeddah, Saudi Arabia were reviewed. The main outcome measured in this study is to describe the histopathological findings of all appendectomy specimens. The secondary outcomes measured in this study were the disease incidence in relation to age, and gender. Moreover, the accuracy of imaging diagnostic tools were also evaluated. Results: This study included 940 participants who underwent an appendectomy procedure. The patients' mean age was 23.4 years (±12.2), with a 3:2 male to female proportion. The incidence in males and females were 59.4% and 40.6%, respectively. Being male (p < 0.001), undergoing preoperative ultrasound (p < 0.001), having elevated white blood cells count (p < 0.001) was significantly associated with accurate diagnosis of acute appendicitis confirmed by histopathology. In this study, the negative cases of appendectomy that account for 14.4% were reported primarily as normal appendix with no inflammatory changes (7.44%) followed by other unexpected findings in the appendectomy specimen (3.93%) that included faecolith, granulomas, mucocele, endometriosis, food/fecal impaction, and schistosomiasis. Our study showed CT sensitivity as a diagnostic tool of acute appendicitis is 90.2%, and its accuracy is 89.4%, while US sensitivity is 46% and its accuracy is 52.4%. Conclusion: Histopathological evaluation after common procedures, such as appendectomy, is essential to avoid missing other pathologies in the appendix. Surgeons should be aware of the uncommon histopathology findings as some disorders call for additional management beyond appendectomy. The clinical details, radiological investigations including CT scan and histopathological diagnoses are required for better management in cases of appendicular lesions.

Model-Based Mid-Level Regulation for Assist-As-Needed Hierarchical Control of Wearable Robots: A Computational Study of Human-Robot Adaptation.

The closed-loop human-robot system requires developing an effective robotic controller that considers models of both the human and the robot, as well as human adaptation to the robot. This paper develops a mid-level controller providing assist-as-needed (AAN) policies in a hierarchical control setting using two novel methods: model-based and fuzzy logic rule. The goal of AAN is to provide the required extra torque because of the robot's dynamics and external load compared to the human limb free movement. The human-robot adaptation is simulated using a nonlinear model predictive controller (NMPC) as the human central nervous system (CNS) for three conditions of initial (the initial session of wearing the robot, without any previous experience), short-term (the entire first session, e.g., 45 min), and long-term experiences. The results showed that the two methods (model-based and fuzzy logic) outperform the traditional proportional method in providing AAN by considering distinctive human and robot models. Additionally, the CNS actuator model has difficulty in the initial experience and activates both antagonist and agonist muscles to reduce movement oscillations. In the long-term experience, the simulation shows no oscillation when the CNS NMPC learns the robot model and modifies its weights to simulate realistic human behavior. We found that the desired strength of the robot should be increased gradually to ignore unexpected human-robot interactions (e.g., robot vibration, human spasticity). The proposed mid-level controllers can be used for wearable assistive devices, exoskeletons, and rehabilitation robots.

Quaternized Chitosan Thiol Hydrogel-Thickened Nanoemulsion: A Multifunctional Platform for Upgrading the Topical Applications of Virgin Olive Oil.

(1) Background: Virgin olive oil (VOO) has attracted the attention of many researchers due to its nutritional and medicinal values. However, VOO's biological applications have been limited due to a lack of precise chemical profiling and approach to increase the physicochemical characteristics, bioactivity, and delivery of its bioactive components; (2) Methods: The current study intended to evaluate the chemical composition of VOO using the GC-MS technique and determine its major components. Furthermore, the effect of incorporating VOO into Tween 80-lecithin nanoemulsion (OONE) and a quaternized trimethyl chitosan-thiol (TMCT) hydrogel-thickened nanoemulsion system (OOHTN) on its physicochemical characteristics and biological potentials will be investigated; (3) Results: The VOO-based NEs' physicochemical properties (particle size and zeta potential) were steady during storage for four weeks owing to the inclusion of the protective TMCT hydrogel network to OONE. Excessive fine-tuning of olive oil nanoemulsion (OONE) and the TMCT protective network's persistent positive charge have contributed to the oil's improved antimicrobial, anti-biofilm, and antioxidant potentials; (4) Conclusions: The Tween 80-lecithin-TMCT nanosystem might provide a unique and multifunctional nanoplatform for efficient topical therapy as well as the transdermal delivery of lipophilic bioactive compounds.

Upgrading the Transdermal Biomedical Capabilities of Thyme Essential Oil Nanoemulsions Using Amphiphilic Oligochitosan Vehicles.

(1) Background: Thymus vulgaris L. (thyme) essential oil (TEO) has gained much attention because of its long history of medicinal usage. However, the lack of precise chemical profiling of the TEO and methods to optimize the bioactivity and delivery of its constituents has hampered its research on quality control and biological function; (2) Methods: The current study aimed to analyze the TEO's chemical composition using the GC-MS method and identify its key components. Another objective of this work is to study the impact of the protective layer of amphiphilic oligochitosan (AOC) on the physicochemical stability and transdermal potentials of TEO multilayer nanoemulsions formulated by the incorporation of TEO, Tween80, lecithin (Lec), and AOC; (3) Results: The AOC protective layer significantly improved the stability of TEO-based NEs as revealed by the constancy of their physicochemical properties (particle size and zeta potential) during storage for a week. Excessive fine-tuning of thyme extract NEs and the AOC protective layer's persistent positive charge have been contributed to the thyme extract's improved anti-inflammatory, transdermal, and anti-melanoma potentials; (4) Conclusions: the AOC-coated NEs could offer novel multifunctional nanoplatforms for effective transdermal delivery of lipophilic bioactive materials.

Impact of Starch Coating Embedded with Silver Nanoparticles on Strawberry Storage Time.

The strawberry has a very short postharvest life due to its fast softening and decomposition. The goal of this research is to see how well a starch-silver nanoparticle (St-AgNPs) coating affects the physical, chemical, and microbiological qualities of strawberries during postharvest life. Additionally, the effect of washing with running water on silver concentration in coated strawberry fruit was studied by an inductively coupled plasma-optical emission spectrometer (ICP-OES). Furthermore, the shelf-life period was calculated in relation to the temperature of storage. Fourier transform infrared-attenuated total reflectance (FTIR-ATR), UV-Visible, and Transmission Electron Microscopic (TEM) were used to investigate the structure of starch-silver materials, the size and shape of AgNPs, respectively. The AgNPs were spherical, with an average size range of 12.7 nm. The coated samples had the lowest weight loss, decay, and microbial counts as compared to the uncoated sample. They had higher total acidity and anthocyanin contents as well. The washing process led to the almost complete removal of silver particles by rates ranging from 98.86 to 99.10%. Finally, the coating maintained strawberry qualities and lengthened their shelf-life from 2 to 6 days at room storage and from 8 to 16 days in cold storage.

Methods for fabricating oxygen releasing biomaterials.

Sustained external supply of oxygen (O2) to engineered tissue constructs is important for their survival in the body while angiogenesis is taking place. In the recent years, the trend towards the fabrication of various O2-generating materials that can provide prolonged and controlled O2 source to the large volume tissue constructs resulted in preventing necrosis associated with the lack of O2 supply. In this review, we explain different methods employed in the fabrication of O2-generating materials such as emulsion, microfluidics, solvent casting, freeze drying, electrospraying, gelation, microfluidic and three-dimensional (3D) bioprinting methods. After discussing pros and cons of each method, we review physical, chemical, and biological characterisation techniques used to analyse the resulting product. Finally, the challenges and future directions in the field are discussed.