4D Printing: The Development of Responsive Materials Using 3D-Printing Technology

Additive manufacturing, widely known as 3D printing, has revolutionized the production of biomaterials. While conventional 3D-printed structures are perceived as static, 4D printing introduces the ability to fabricate materials capable of self-transforming their configuration or function over time in response to external stimuli such as temperature, light, or electric field. This transformative technology has garnered significant attention in the field of biomedical engineering due to its potential to address limitations associated with traditional therapies. Here, we delve into an in-depth review of 4D-printing systems, exploring their diverse biomedical applications and meticulously evaluating their advantages and disadvantages. We emphasize the novelty of this review paper by highlighting the latest advancements and emerging trends in 4D-printing technology, particularly in the context of biomedical applications.

Development and Validation of a Simple, Fast, and Accessible HPLC-UV Method for Cannabinoids Determination in Cannabis sativa L. Extracts and Medicinal Oils

INTRODUCTION

Cannabis sativa L. is a well-recognized medicinal plant. Cannabis regulations in Argentina are insufficient to solve the problem of patient access to full-spectrum cannabis-based products. So, the market of artisanal products with unknown quality and dosage of cannabinoids is increasing, and so is the local demand and need for analyzing these products. However, much of the latest validated methodologies for cannabinoid quantification include expensive instrumentation that is not always available in laboratories of health institutions in Argentina.

METHODS

The aim of this work was to develop and validate a simple and rapid HPLC-UV method for the identification and quantification of principal cannabinoids in cannabis resins, inflorescences, and medicinal oils using standard HPLC equipment. The cannabinoids selected for validation were cannabidiol acid (CBDA), cannabigerol (CBG), cannabidiol (CBD), cannabinol (CBN), delta-9-tetrahydrocannabinol (Δ9-THC), cannabichromene (CBC), and tetrahydrocannabinol acid (THCA). A method for the simultaneous identification and quantification of these 7 main cannabinoids was developed and then validated. Some data parameters were comparable to other reports with more sophisticated analytical instruments for the analysis of cannabis. The assessed limits of detection and the limits of quantitation ranged from 0.9 to 3.66 μg/mL and 2.78 to 11.09 μg/mL, respectively. The concentration-response relationship of the method indicated a linear relationship between the concentration and peak area with R2 values of > 0.99 for all 7 cannabinoids.

RESULTS

The relative standard deviation (RSD%) varied from 2.34 to 4.82 for intraday repeatability and from 1.16 to 3.15 for interday repeatability. The percentage of recovery values was between 94 to 115% (resins) and 80 to 103% (inflorescence extract). The cannabis industry is growing rapidly, and there is a need for reliable testing methods to ensure the safety and efficacy of cannabis products. In addition, current methods for cannabinoid analysis are often time-consuming and expensive, while the HPLC-UV method herein reported is a simple, rapid, accurate, and cost-effective alternative for the analysis of cannabinoids in cannabis resins, inflorescences, and medicinal oils.

CONCLUSION

This method will be proposed to be included in the Cannabis sativa L. monograph of the Argentine Pharmacopoeia.

Entourage Effect And Analytical Chemistry: Chromatography As A Tool In The Analysis Of The Secondary Metabolism Of Cannabis Sativa L

Abstract:

Cannabis sativa L. has been used as medicine for thousands of years. Since the early identification of tetrahydrocannabinol (THC) in 1960, pharmacological activities were attributed to a group of unique structures named cannabinoids. For decades, research and development were applied to determine different cannabinoids and their medicinal properties. Nowadays there is evidence that the therapeutic benefits of the plant are based on the synergy of cannabinoids and other secondary metabolites such as terpenes and flavonoids. Differences between the medical performance of isolated compounds like cannabidiol (CBD) or THC and full-spectrum plant extracts are notable. Indeed, the superiority of the last one is provoked by the synergy between various different compounds. This improved medicinal effect is called the entourage effect. Chromatography has become the method of choice for the determination of cannabinoids, terpenes, and flavonoids, so it represents an excellent tool for a proper characterization of the plant and plant derived products. The objective of characterization relies not only in analyzing the fingerprint of cannabis, but also to identify different chemotypes for medical purposes. To understand the contributions of each natural product to this “entourage effect”, this review presents an in-depth analysis of the utilization of High-performance liquid chromatography (HPLC), Gas chromatography (GC) and other methods for the analysis of phytocomponents of Cannabis sativa L. In this sense, a representative number of examples and advances made in the field together with limitations and future needs are provided. It can be concluded that standardized protocols and quality control policies and procedures are necessary for the comprehensive analysis of cannabis extracts and derivatives.

Green Synthesized Nanomaterials for Safe Technology in Sustainable Agriculture

Nanotechnology is a new emerging cutting-edge technology in the 21st century and has applications in medical, cosmetics, electronics, energy, food, agriculture, and many sectors. Nanomaterials (NMs) are the main component of nanotechnology. NMs prepared by chemical routes are very hazardous and not safe for life. Therefore, attempts are being made to prepare NMs via different green routes. It is expected that nanotechnology using green synthesized NMs will be safe. At the same time, green synthesized nanomaterials will be cost-effective. In this chapter, the applications of green synthesized NMs in agriculture have been discussed in detail.

Progress in Gelatin as Biomaterial for Tissue Engineering

Tissue engineering has become a medical alternative in this society with an ever-increasing lifespan. Advances in the areas of technology and biomaterials have facilitated the use of engineered constructs for medical issues. This review discusses on-going concerns and the latest developments in a widely employed biomaterial in the field of tissue engineering: gelatin. Emerging techniques including 3D bioprinting and gelatin functionalization have demonstrated better mimicking of native tissue by reinforcing gelatin-based systems, among others. This breakthrough facilitates, on the one hand, the manufacturing process when it comes to practicality and cost-effectiveness, which plays a key role in the transition towards clinical application. On the other hand, it can be concluded that gelatin could be considered as one of the promising biomaterials in future trends, in which the focus might be on the detection and diagnosis of diseases rather than treatment.

Building the Bridge From Aquatic Nanotoxicology to Safety by Design Silver Nanoparticles

Nanotechnologies have rapidly grown, and they are considered the new industrial revolution. However, the augmented production and wide applications of engineered nanomaterials (ENMs) and nanoparticles (NPs) inevitably lead to environmental exposure with consequences on human and environmental health. Engineered nanomaterial and nanoparticle (ENM/P) effects on humans and the environment are complex and largely depend on the interplay between their peculiar properties such as size, shape, coating, surface charge, and degree of agglomeration or aggregation and those of the receiving media/body. These rebounds on ENM/P safety and newly developed concepts such as the safety by design are gaining importance in the field of sustainable nanotechnologies. This article aims to review the critical characteristics of the ENM/Ps that need to be addressed in the safe by design process to develop ENM/Ps with the ablility to reduce/minimize any potential toxicological risks for living beings associated with their exposure. Specifically, we focused on silver nanoparticles (AgNPs) due to an increasing number of nanoproducts containing AgNPs, as well as an increasing knowledge about these nanomaterials (NMs) and their effects. We review the ecotoxicological effects documented on freshwater and marine species that demonstrate the importance of the relationship between the ENM/P design and their biological outcomes in terms of environmental safety.

The 3D Bioprinted Scaffolds for Wound Healing

Skin tissue engineering and regeneration aim at repairing defective skin injuries and progress in wound healing. Until now, even though several developments are made in this field, it is still challenging to face the complexity of the tissue with current methods of fabrication. In this review, short, state-of-the-art on developments made in skin tissue engineering using 3D bioprinting as a new tool are described. The current bioprinting methods and a summary of bioink formulations, parameters, and properties are discussed. Finally, a representative number of examples and advances made in the field together with limitations and future needs are provided.

Collagen Hydrogels Loaded with Silver Nanoparticles and Cannabis Sativa Oil

Wounds represent a major healthcare problem especially in hospital-associated infections where multi-drug resistant strains are often involved. Nowadays, biomaterials with therapeutic molecules play an active role in wound healing and infection prevention. In this work, the development of collagen hydrogels loaded with silver nanoparticles and Cannabis sativa oil extract is described. The presence of the silver nanoparticles gives interesting feature to the biomaterial such as improved mechanical properties or resistance to collagenase degradation but most important is the long-lasting antimicrobial effect. Cannabis sativa oil, which is known for its anti-inflammatory and analgesic effects, possesses antioxidant activity and successfully improved the biocompatibility and also enhances the antimicrobial activity of the nanocomposite. Altogether, these results suggest that this novel nanocomposite biomaterial is a promising alternative to common treatments of wound infections and wound healing.

Recent Advances in Micro-Electro-Mechanical Devices for Controlled Drug Release Applications

In recent years, controlled release of drugs has posed numerous challenges with the aim of optimizing parameters such as the release of the suitable quantity of drugs in the right site at the right time with the least invasiveness and the greatest possible automation. Some of the factors that challenge conventional drug release include long-term treatments, narrow therapeutic windows, complex dosing schedules, combined therapies, individual dosing regimens, and labile active substance administration. In this sense, the emergence of micro-devices that combine mechanical and electrical components, so called micro-electro-mechanical systems (MEMS) can offer solutions to these drawbacks. These devices can be fabricated using biocompatible materials, with great uniformity and reproducibility, similar to integrated circuits. They can be aseptically manufactured and hermetically sealed, while having mobile components that enable physical or analytical functions together with electrical components. In this review we present recent advances in the generation of MEMS drug delivery devices, in which various micro and nanometric structures such as contacts, connections, channels, reservoirs, pumps, valves, needles, and/or membranes can be included in their design and manufacture. Implantable single and multiple reservoir-based and transdermal-based MEMS devices are discussed in terms of fundamental mechanisms, fabrication, performance, and drug release applications.

Toxicity evaluation of nanocrystalline silver-impregnated coated dressing on the life cycle of worm Caenorhabditis elegans

In recent times, however, due to the emergence of bacterial strains with resistance to conventional antibiotics, silver has again gained attention as an alternative for developing new efficient bactericides, including the use of silver nanoparticles (AgNPs). However, the improper disposal of these items after use may cause toxicological effects on organisms in the environment. To evaluate the potential environmental hazard of nanosilver-coated dressings, the nematode Caenorhabditis elegans was chosen as a test organism. The assays were conducted in 24-well plates that contain four different sizes of coated dressing to obtain different concentrations. L1 and L4 C. elegans larval stages were exposed to these nanosilver concentrations. Dressing cutouts were arranged between two layers of agar for 3 days and Escherichia coli (OP 50 strain) was added as food source for the worms. After the exposure period, growth, reproduction, fertility, silver concentration in the medium and the concentration of reactive oxygen species (ROS) in the worms were evaluated. Scanning and transmission electron microscopy analyses were performed on the coated dressings, as well as analyses of zeta potential, ionic release and antibacterial power in two bacterial strains (Pseudomonas aeruginosa and Staphylococcus aureus). It was verified the antibacterial power of the coated dressing, in both bacteria strains tested. Characterization of the coated dressing indicated heterogeneous nanoparticles, as well as distinct zeta potentials for the medium in water and saline medium (0.9% NaCl). L1 larval worms exposed to nanosilver-coated dressing showed a high ROS concentration and reductions in growth, fertility and reproduction. Worms exposed to the coated dressing during the L4 stage showed almost no response. Overall, the obtained results indicate the potential environmental hazard of nanosilver-coated dressings.

Development of pH-responsive biopolymer-silica composites loaded with Larrea divaricata Cav. extract with antioxidant activity

A detailed study of biomaterials is mandatory to comprehend their feasible biomedical applications in terms of drug delivery and tissue regeneration. Particularly, mucoadhesive biopolymers such as chitosan (chi) and carboxymethylcellulose (CMC) have become interesting biomaterials regards to their biocompatibility and non-toxicity for oral mucosal drug delivery. In this work, pH-responsive biopolymer-silica composites (Chi-SiO₂, Chi-CMC-SiO₂) were developed. These two types of composites presented a different swelling behavior due to the environmental pH. Moreover, the nanocomposites were loaded with aqueous Larrea divaricata Cav. extract (Ld), a South American plant which presents antioxidant properties suitable for the treatment of gingivoperiodontal diseases. Chi-CMC-SiO₂ composites showed the highest incorporation and reached the 100% of extract release in almost 4 days while they preserved their antioxidant properties. In this study, thermal and swelling behavior were pointed out to show the distinct water-composite interaction and therefore to evaluate their mucoadhesivity. Furthermore, a cytotoxicity test with 3T3 fibroblasts was assessed, showing that in both composites the addition of Larrea divaricata Cav. extract increased fibroblast proliferation. Lastly, preliminary in vitro studies were performed with simulated body fluids. Indeed, SEM-EDS analysis indicated that only chi-SiO₂ composite may provide an environment for possible biomineralization while the addition of CMC to the composites discouraged calcium accumulation. In conclusion, the development of bioactive composites could promote the regeneration of periodontal tissue damaged throughout periodontal disease and the presence of silica nanoparticles could provide an environment for biomineralization.

Advances in collagen, chitosan and silica biomaterials for oral tissue regeneration: from basics to clinical trials

Different materials have distinct surface and bulk characteristics; each of them potentially useful for the treatment of a particular wound or disease.

Dye–collagen interactions. Mechanism, kinetic and thermodynamic analysis

Dye–collagen interactions. Mechanism, kinetic and thermodynamic analysis.

Validation of a capillary electrophoresis method for the analysis of ibandronate related impurities

A capillary zone electrophoretic (CZE) method has been developed for the determination of impurities (phosphyte and phosphate) in technical-grade ibandronate, which is a potent nitrogen-containing bisphosphonate. Successful separation of the drug from the impurities was achieved using 1mM tetradecyl-trimethyl-ammonium bromide (TTAB) and 5mM potassium chromate (pH 10.0) as background electrolyte with an indirect detection at 254 nm. The optimised method was validated for specificity, precision, linearity and accuracy. The limit of detection (LOD) was 2 microg/mL and the limit of quantification (LOQ) was 7 microg/mL for both phosphyte and phosphate. The developed CZE method used to determine phosphyte and phosphate as bisphosphonates impurities can be used to evaluate the quality of regular production samples of ibandronate.

Antimicrobial activity on glass materials subject to disinfectant xerogel coating

The antimicrobial compound dodecyl-di(aminoethyl)-glycine was immobilized in a silicon oxide xerogel matrix and used for glass surface coating. Coated glasses were tested for surface antimicrobial activity. The utilization of tetraethoxysilane (TEOS) as a silicon oxide polymer precursor, using the dip-coating process, allowed for the generation of transparent thin films over glass surfaces. Different concentrations of the antimicrobial compound were used to generate the coatings. The presence of dodecyl-di(aminoethyl)-glycine on coated and uncoated slides was analyzed by FT-IR spectra. Coated glass slides were exposed to suspensions of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus for 24 h. Surface contamination was evaluated by the microbial plate count technique. When antimicrobial-coated glasses were compared with antimicrobial-free coated glasses, the former showed greater than 99% reduction of colony-forming units (cfu) for E. coli and P. aeruginosa, when 1% of antimicrobial was present in the coating solution. The same percentage of reduction for S. aureus was achieved when 1.5% of the antimicrobial was present in the coating solution. In a direct inhibition test on agar plates, no inhibitory zone was observed, indicating that the antimicrobial did not diffuse into the media.