Advances in polysaccharide nanocrystals as pharmaceutical excipients

Recent progress in nanocellulose-based biocomposites for bone tissue engineering and wound healing applications

Nanocellulose (NC) is considered as promising biomaterial owing to its stiffness, renewability, high strength, and biodegradability. NC is classified into three types such as cellulose nanocrystals (CNCs), bacterial nanocellulose (BNC), and cellulose nanofibers (CNFs), and they differ with each other in terms of size, mechanical behaviour, morphology, and crystallinity. The development of biocomposites with nanocellulose as reinforcing agent has gained much attention among researchers owing to their promising applications in various sectors. The thermal, mechanical, and biodegradable properties of both synthetic and natural polymers can be enhanced by reinforcing them with nanocellulose. The fabrication of NC-based biocomposites can be achieved by employing different techniques such as solution casting, resin impregnation and melt compounding methods. The porosity, tensile modulus, tensile strength, MVTR (moisture-vapour transmission rate), biocompatibility, hydrophilic, water retention ability, bio-adhesiveness and hemocompatibility are the essential properties of tissue engineering scaffolds and wound dressing materials, and these properties can be optimized by reinforcing them with NC. This review intends to focus on the reinforcing effect of NC on the physicochemical and thermo-mechanical characteristics of NC-based biocomposites. This review also aims to summarize the utilization of NC-based biocomposites in tissue engineering scaffolds and wound dressing applications.

A review on polysaccharide-based tumor targeted drug nanodelivery systems

The tumor-targeted drug delivery system (TTDNS) uses nanocarriers to transport chemotherapeutic agents to target tumor cells or tissues precisely. This innovative approach considerably increases the effective concentration of these drugs at the tumor site, thereby enhancing their therapeutic efficacy. Many chemotherapeutic agents face challenges, such as low bioavailability, high cytotoxicity, and inadequate drug resistance. To address these obstacles, TTDNS comprising natural polysaccharides have gained increasing popularity in the field of nanotechnology owing to their ability to improve safety, bioavailability, and biocompatibility while reducing toxicity. In addition, it enhances permeability and allows for controlled drug delivery and release. This review focuses on the sources of natural polysaccharides and their direct and indirect mechanisms of anti-tumor activity. We also explored the preparation of various polysaccharide-based nanocarriers, including nanoparticles, nanoemulsions, nanohydrogels, nanoliposomes, nanocapsules, nanomicelles, nanocrystals, and nanofibers. Furthermore, this review delves into the versatile applications of polysaccharide-based nanocarriers, elucidating their capabilities for in vivo targeting, controlled release, and responsiveness to endogenous and exogenous stimuli, such as pH, reactive oxygen species, glutathione, light, ultrasound, and magnetic fields. This sophisticated design substantially enhances the chemotherapeutic efficacy of the encapsulated drugs at tumor sites and provides a basis for preclinical and clinical research. However, the in vivo stability, drug loading, and permeability of these preparations into tumor tissues still need to be improved. Most of the currently developed biomarker-sensitive polysaccharide nanocarriers are still in the laboratory stage, more innovative delivery mechanisms and clinical studies are needed to develop commercial nanocarriers for medical use.

Oxidation and carboxymethylation of starch nanocrystals: Crystalline structure, dispersibility, dispersion stability, and protein loading efficiency study

Herein, oxidation and carboxymethylation were employed to improve the dispersibility and stability of starch nanocrystal (SNC) in aqueous solution by enhancing intermolecular electrostatic repulsion between SNCs, as well as to promote their protein loading capacity. FT-IR, XPS, and NMR analyses confirmed the successful surface modification of SNC, with oxidation likely occurring at the C6-OH position of anhydroglucose units. Oxidation selectively degraded the amorphous parts with small molecular weight, while carboxymethylation removed surface hydrocarbons, promoting relative crystallinity, crystalline lamellae thickness, and structural compactness in the oxidized and carboxymethylated SNC (OSNC and CSNC). Morphologically, OSNC and CSNC exhibited regular square shapes, with CSNC showing a more uniform appearance. Both OSNC and CSNC displayed small hydrodynamic size and high zeta potential, along with high transparency suspensions at pH 7, indicating good dispersibility and stability driven by electrostatic repulsion. Only OSNC, with the highest degree of oxidation, maintained stability at pH 3, due to its strong buffer capacity against protonation. Furthermore, both OSNC and CSNC showed enhanced protein loading capacity, with OSNC achieving higher capacity than CSNC, suggesting its potential as a protein delivery carrier. This work offers alternative strategies to reduce interparticle aggregation in SNCs, broadening their industrial applications.

Deaggregation of micronized insoluble drugs by incorporating mannitol form α

Micronization is frequently employed to increase the dissolution of poorly soluble drugs, but it easily led to powder aggregation and difficult to mix well on the micro level with poor content uniformity and erratic dissolution behavior. Mannitol is the most commonly used pharmaceutical excipient, and its β form (β-mannitol) is commercially available and extensively investigated, whereas form α (α-mannitol) remain poorly understood. Here, this study demonstrated that α-mannitol could significantly eliminate aggregation phenomena of micronized drugs (i.e., lurasidone hydrochloride, indomethacin and ibuprofen) after general mixing, while β-mannitol could not. In addition, the drug dissolutions after mixing with α-mannitol were also significantly higher than that with β one. This stemmed from the different molecular orientation on their dominant crystal facets, resulting in greater number of unsaturated hydrogen bonds site (0.050 Å-2vs 0.042 Å-2) on α-mannitol's crystal facet {013}, leading to more positive charge and negative charge site and higher surface energy (64.42 mJ/m2vs 50.26mJ/m2). Subsequently, this increased the interaction between drug and α-mannitol, which is higher than interaction between drug itself, also higher than interaction between drug and β-mannitol, resulting in adhesion of drug powder on α-mannitol rather than cohesion into aggregates. Moreover, after 30 days of storage at 60 °C or 92.5 % relative humidity, the polymorphic purity of α-mannitol remained above 99 %, indicating good polymorphic stability during transportation and storage. This work illustrates that α-mannitol exhibited great potential to serve as a new pharmaceutical excipient in solid dosage forms. We believe that utilizing the benefits of polymorphism and mitigating their limitations will exert great potential for the development of functional pharmaceutical excipients.

Nanocrystal Formulation to Enhance Oral Absorption of Silybin: Preparation, In Vitro Evaluations, and Pharmacokinetic Evaluations in Rats and Healthy Human Subjects

Despite the various therapeutic benefits and high tolerance of orally administered silybin, poor water-solubility can be the main restrictive physicochemical feature, which results in low oral bioavailability in the absorption. A milk thistle nanocrystal formulation (HM40) was prepared using a modified wet-milling method. Comprehensive characterization was performed to determine the physical morphology, crystallinity, and physicochemical properties. The long-term stability was evaluated over 24 months. In vitro silybin release was assessed at pH 1.2 for 2 h, followed by pH 6.8 for 4 h. Finally, in vivo pharmacokinetic studies were conducted in rats and healthy human volunteers. HM40 exhibited a nanocrystal structure maintaining crystallinity and enhanced the solubility and dissolution of silybin compared to that of the raw material. The stability over 24 months revealed consistent surface morphology, particle size, silybin content, and solubility. In vitro release profiles indicated a significant increase in the silybin release from HM40. In vivo pharmacokinetic studies demonstrated that HM40 showed 2.61- and 1.51-fold higher oral bioavailability in rats and humans, respectively, than that of the reference capsule. HM40 formulation presents a stable and promising approach for the oral delivery of poorly water-soluble silybin, with the potential for use in pharmaceutical formulations containing milk thistle.

Simple Genomic Traits Predict Rates of Polysaccharide Biodegradation

Natural and chemically modified polysaccharides are extensively employed across a wide array of industries, leading to their prevalence in the waste streams of industrialized societies. With projected increasing demand, a pressing challenge is to swiftly assess and predict their biodegradability to inform the development of new sustainable materials. In this study, we developed a scalable method to evaluate polysaccharide breakdown by measuring microbial growth and analyzing microbial genomes. Our approach, applied to polysaccharides with various structures, correlates strongly with well-established regulatory methods based on oxygen demand. We show that modifications to the polysaccharide structure decreased degradability and favored the growth of microbes adapted to break down chemically modified sugars. More broadly, we discovered two main types of microbial communities associated with different polysaccharide structures─one dominated by fast-growing microbes and another by specialized degraders. Surprisingly, we were able to predict biodegradation rates based only on two genomic features that define these communities: the abundance of genes related to rRNA (indicating fast growth) and the abundance of glycoside hydrolases (enzymes that break down polysaccharides), which together predict nearly 70% of the variation in polysaccharide breakdown. This suggests a trade-off, whereby microbes are either adapted for fast growth or for degrading complex polysaccharide chains, but not both. Finally, we observe that viral elements (prophages) encoded in the genomes of degrading microbes are induced in easily degradable polysaccharides, leading to complex dynamics in biomass accumulation during degradation. In summary, our work provides a practical approach for efficiently assessing polymer degradability and offers genomic insights into how microbes break down polysaccharides.

Facile Preparation of Lightweight Natural Rubber Nanocomposite Foams with High Wear Resistance

The light weight and excellent mechanical properties of rubber foam means that it is widely applied in the aerospace, automobile, and military industries. However, its poor wear resistance contributes directly to a short service life and a waste of resources. Therefore, the design and development of high-wear-resistance rubber foam are of great importance. In this work, some nanoclay/rubber composite foams were prepared by blending NR/EPDM with different kinds of nanoclays containing layered double hydroxide (LDH), montmorillonite (MMT), and attapulgite (ATP) to indicate the effects of the kinds of nanoclays on the wear resistance and mechanical properties of nanoclay/rubber composite foams. The kinds of nanoclay/rubber composite foams were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The results showed that nanoclay has heterogeneous nucleation in composite foamed materials. The wear resistance of the composite foam materials with added nanoclay was significantly improved, and the MMT of the lamellar structure (increased by 43.35%) and LDH (increased by 38.57%) were significantly higher than the ATP of the rod-like structure (increased by 13.04%). The improvement in the wear resistance of the matrix was even higher. Compared with other foams, the wear resistance of the OMMT-NR/EPDM foam (increased by 58.89%) with a lamellar structure had the best wear resistance. Due to the increase in the lamellar spacing of the modified OMMT, the exfoliation of worn rubber molecular chains has little effect on the adjacent molecular chains, which prevents the occurrence of crimp wear and further improves the wear resistance of composite foaming materials. Therefore, this work lays the foundation for the manufacturing of rubber foams for wear-resistant applications.

Anisotropic materials based on carbohydrate polymers: A review of fabrication strategies, properties, and applications

Anisotropic structures exist in almost all living organisms to endow them with superior properties and physiological functionalities. However, conventional artificial materials possess unordered isotropic structures, resulting in limited functions and applications. The development of anisotropic structures on carbohydrates is reported to have an impact on their properties and applications. In this review, various alignment strategies for carbohydrates (i.e., cellulose, chitin and alginate) from bottom-up to top-down strategies are discussed, including the rapidly developed innovative technologies such as shear-induced orientation through extrusion-based 3D/4D printing, magnetic-assisted alignment, and electric-induced alignment. The unique properties and wide applications of anisotropic carbohydrate materials across different fields, from biomedical, biosensors, smart actuators, soft conductive materials, to thermal management are also summarized. Finally, recommendations on the selection of fabrication strategies are given. The major challenge lies in the construction of long-range hierarchical alignment with high orientation degree and precise control over complicated architectures. With the future development of hierarchical alignment strategies, alignment control techniques, and alignment mechanism elucidation, the potential of anisotropic carbohydrate materials for scalable manufacture and clinical applications will be fully realized.

Antimicrobial mechanisms of g-C3 N4 @ZnO against oomycetes Phytophthora capsici: from its metabolism, membrane structures and growth

BACKGROUND

Phytophthora capsici, a refractory and model oomycete plant pathogen, especially threatens multiple vegetable crops. A limited number of chemical pesticides play a vital role in controlling oomycete plant diseases. However, this approach often leads to excessive use of chemical agent, exacerbates environmental issues and more and more drug-resistant strains of oomycete. Therefore, it is imperative to devise innovative solutions that can effectively address the infection of oomycete while maintaining high levels of environmental sustainability and low toxicity.

RESULTS

In this study, g-C3 N4 @ZnO heterostructure was synthesized and characterized. The g-C3 N4 @ZnO showed higher toxicity on Phytophthora capsici than graphitic carbon nitride (g-C3 N4 ) nanosheets and zinc oxide (ZnO) nanoparticles in vitro and in vivo. Except the hyphal growth of Phytophthora capsici, their germination rate of spores, sporangium formation and number of spores were all suppressed by g-C3 N4 @ZnO heterostructure. Furthermore, we found that this g-C3 N4 @ZnO heterostructure has higher photocatalytic activity under visible light, which potentially enhanced the reactive oxygen species (ROS) mediated stress on Phytophthora capsici. Ultrastructural morphology, global changes of gene expression and weighted gene co-expression network analysis all supported that the anti-oomycete activity of g-C3 N4 @ZnO was manifested in the destruction of membrane system and inhibition of multiple metabolisms of Phytophthora capsici under visible irradiation, which also could be attributed to the ROS and zinc ion (Zn2+ ) mediated stress.

CONCLUSION

This works offers a novel oomycete disease management strategy by using g-C3 N4 @ZnO, which were attributed to the ROS stress, destruction of membrane system and inhibition of multiple metabolisms. © 2023 Society of Chemical Industry.

Nanocellulose-based platforms as a multipurpose carrier for drug and bioactive compounds: From active packaging to transdermal and anticancer applications

The nanocellulose has unique characteristics, such as biocompatibility, good mechanical strength, and low cytotoxicity. The nanocellulose crystalline portion is responsible for good mechanical resistance, while the amorphous portion is responsible for flexibility. Such features make it a promising candidate for multiple applications related to the modulation of substance release: targeted cancer therapy, transdermal drug delivery, and controlled-release packaging materials. Thus, in this study, we discussed nanocellulose as a multipurpose material for drug delivery and bioactive compound carriers in controlled delivery systems with varied applications in pharmaceutic fields. Herein, we focus on understanding key factors such as i) polymer-drug interactions and surface modification strategies in controlled release rates, ii) therapeutic efficacy, and iii) biocompatibility aspects. The tunable chemistry surface plays a fundamental approach limiting the quick release of active substances in drug delivery systems. Several works on a pre-clinical stage of investigation were overviewed, reporting robust evidence on nanocellulose to design bioactive compounds/drug delivery carriers based on stimuli-responsive drug release and controlled delivery systems for higher efficiency in cancer therapies, purposing target therapy and reduced side effects. Nanocellulose was also identified as a solid candidate material in active packaging for pharmaceutical products. Cellulose nanocrystals and bacterial cellulose demonstrated strong potential to overcome the challenge of controlled release profile and open novel insights in advanced active packaging materials for pharmaceutics with controlled release of antioxidant and antimicrobial substances. Moreover, the concept overview in this work might be extended in active food packaging technologies to flavor-releasing/absorbing systems or antimicrobial/antioxidant carriers for extending the shelf life of foods.

Classification and design strategies of polysaccharide-based nano-nutrient delivery systems for enhanced bioactivity and targeted delivery: A review

Since many nutrients are highly sensitive, they cannot be absorbed and utilized efficiently by the body. Using nano-delivery systems to encapsulate nutrients is an effective method of solving the problems associated with the application of nutrients at this stage. Polysaccharides, as natural biomaterials, have a unique chemical structure, ideal biocompatibility, biodegradability and low immunogenicity. This makes polysaccharides powerful carriers that can enhance the biological activity of nutrients. However, the true role of polysaccharide-based delivery systems requires an in-depth understanding of the structural and physicochemical characteristics of polysaccharide-based nanodelivery systems, as well as effective modulation of the intestinal delivery mechanism and the latest advances in nano-encapsulation. This review provides an overview of polysaccharide-based nano-delivery systems dependent on different carrier types, emphasizing recent advances in the application of polysaccharides, a biocomposite material designed for nutrient delivery systems. Strategies for polysaccharide-based nano-delivery systems to enhance the bioavailability of orally administered nutrients from the perspective of the intestinal absorption barrier are presented. Characterization methods for polysaccharide-based nano-delivery systems are presented as well as an explanation of the formation mechanisms behind nano-delivery systems from the perspective of molecular forces. Finally, we discussed the challenges currently facing polysaccharide-based nano-delivery systems as well as possible future directions for the future.

CD-MOFs: From preparation to drug delivery and therapeutic application

Cyclodextrin metal-organic frameworks (CD-MOFs) show considerable advantages of edibility, degradability, low toxicity, and high drug loading, which have attracted enormous interest, especially in drug delivery. This review summarizes the typical synthesis approaches of CD-MOFs, the drug loading methods, and the mechanism of encapsulation and release. The influence of the structure of CD-MOFs on their drug encapsulation and release is highlighted. Finally, the challenges CD-MOFs face are discussed regarding biosafety assessment systems, stability in aqueous solution, and metal ion effect.

Advances in polysaccharides for probiotic delivery: Properties, methods, and applications

Probiotics are essential to improve the health of the host, whereas maintaining the viability of probiotics in harsh environments remains a challenge. Polysaccharides have non-toxicity, excellent biocompatibility, and outstanding biodegradability, which can protect probiotics by forming a physical barrier and show a promising prospect for probiotic delivery. In this review, we summarize polysaccharides commonly used for probiotic microencapsulation and introduce the microencapsulation technologies, including extrusion, emulsion, spray drying, freeze drying, and electrohydrodynamics. We discuss strategies for better protection of probiotics and introduce the applications of polysaccharides-encapsulated probiotics in functional food, oral formulation, and animal feed. Finally, we propose the challenges of polysaccharides-based delivery systems in industrial production and application. This review will help provide insight into the advances and challenges of polysaccharides in probiotic delivery.

A new sight separation for collecting starch nanocrystals with small size and high crystallinity based on the hydrolysis mechanism

To prevent starch nanocrystals (SNCs) that are generated at an early stage from being hydrolyzed excessively, this study proposed a new separation method, named "neutral dispersion and acidic precipitation." SNCs were prepared from waxy potato starch by sulfuric acid hydrolysis. Based on the results of kinetics and molecular weight, the hydrolysis was divided into three stages, e.g., rapid (initial 1 day), medium (subsequent 1 day) and slow stage (2-5 days). The rapid and medium stages were related to the degradation of amorphous region in starch, and the slow stage mainly referred to SNC release. Therefore, the method was developed to separate SNCs at the slow stage. After centrifugation at 6000 rpm, large particles were removed from the SNC suspension under pH 7. The SNCs with small average size and crystallite size, high relative crystallinity (RC), and high dispersion stability in the supernatant were retained and were then precipitated entirely under pH 5, because pH 5 led to the reduction of dispersion stability of SNCs. Meanwhile, the hydrothermal and dry-thermal stability of separated SNCs were significantly promoted. The separation method has the potential in SNC preparation for increasing the yield and collecting products with small size and high RC.

Chitin nanocrystals supported copper: a new nanomaterial with high activity with P. syringae pv. Tabaci

BACKGROUND

The application of chemical pesticides in control of plant bacterial disease may cause potential environmental pollution. Herein, based on the resistance-inducing ability and the special rod-like structure with high aspect ratio of bio-derived chitin nanocrystals (ChNC), a new Cu composite rod-like nanoparticle was fabricated (ChNC@Cu). The antibacterial activity of the composite nanoparticle was systematically studied, and its safety was evaluated.

RESULTS

TEM, FTIR, ICP and other characterization methods proved that ChNC@Cu is a nano rod-like structure, with a Cu²⁺ loading capacity of 2.63%. In vitro experiments showed that the inhibition rate of ChNC@Cu to P. syringae pv. tabaci was more than 95% when the copper content was 41.6 μg mL^-1 . In vivo experiments showed that ChNC@Cu had a good protective effect on P. syringae pv. tabaci of tobacco. In addition, ChNC@Cu exhibited stronger antibacterial activity than Thiodiazole copper (TC) at the same copper content. The study on the antibacterial mechanism of ChNC@Cu proved that ChNC@Cu caused bacterial death by destroying the bacterial cell membrane structure and damaging the DNA bacteria. And ChNC@Cu is highly safe for plants and can promote seed germination and plant growth.

CONCLUSION

The special rod-like structure of ChNC can enrich Cu²⁺ to form ChNC@Cu. ChNC@Cu has a good protective effect on bacterial infection of tobacco, and achieves a great antibacterial activity at low Cu²⁺ concentration, which indicated that ChNC@Cu has induced resistance and antibacterial effect. As a novel green nanofungicide, ChNC@Cu has high potential application value in control of agricultural bacterial diseases. © 2023 Society of Chemical Industry.

Green Topochemical Esterification Effects on the Supramolecular Structure of Chitin Nanocrystals: Implications for Highly Stable Pickering Emulsions

In nature, chitin is organized in hierarchical structures composed of nanoscale building blocks that show outstanding mechanical and optical properties attractive for nanomaterial design. For applications that benefit from a maximized interface such as nanocomposites and Pickering emulsions, individualized chitin nanocrystals (ChNCs) are of interest. However, when extracted in water suspension, their individualization is affected by ChNC self-assembly, requiring a large amount of water (above 90%) for ChNC transport and stock, which limits their widespread use. To master their individualization upon drying and after regeneration, we herein report a waterborne topochemical one-pot acid hydrolysis/Fischer esterification to extract ChNCs from chitin and simultaneously decorate their surface with lactate or butyrate moieties. Controlled reaction conditions were designed to obtain nanocrystals of a comparable aspect ratio of about 30 and a degree of modification of about 30% of the ChNC surface, under the rationale to assess the only effect of the topochemistry on ChNC supramolecular organization. The rheological analysis coupled with polarized light imaging shows how the nematic structuring is hindered by both surface ester moieties. The increased viscosity and elasticity of the modified ChNC colloids indicate a gel-like phase, where typical ChNC clusters of liquid crystalline phases are disrupted. Pickering emulsions have been prepared from lyophilized nanocrystals as a proof of concept. Our results demonstrate that only the emulsions stabilized by the modified ChNCs have excellent stability over time, highlighting that their individualization can be regenerated from the dry state.

Polysaccharide-based formulations as potential carriers for pulmonary delivery - A review of their properties and fates

Polysaccharides can be elite carriers for therapeutic molecules due to their versatility and low probability to trigger toxicity and immunogenic responses. Local and systemic therapies can be achieved through particle pulmonary delivery, a promising non-invasive alternative. Successful pulmonary delivery requires particles with appropriate flowability to reach alveoli and avoid premature clearance mechanisms. Polysaccharides can form micro-, nano-in-micro-, and large porous particles, aerogels, and hydrogels. Herein, the characteristics of polysaccharides used in drug formulations for pulmonary delivery are reviewed, providing insights into structure-function relationships. Charged polysaccharides can confer mucoadhesion, whereas the ability for specific sugar recognition may confer targeting capacity for alveolar macrophages. The method of particle preparation must be chosen considering the properties of the components and the delivery device to be utilized. The fate of polysaccharide-based carriers is dependent on enzyme-triggered hydrolytic and/or oxidative mechanisms, allowing their complete degradation and elimination through urine or reutilization of released monosaccharides.

Surface-charged starch nanocrystals from glutinous rice: Preparation, crystalline properties and cytotoxicity

The high-amylopectin glutinous rice is used in this study for the preparation of starch nanocrystals (SNCs) with the acid hydrolysis and enzymatic treatment. The fabricated SNC is carried out the surface modifications by phosphorylation and cationization to produce the nanocrystals with the charged surface. Four kinds of SNCs are obtained with the different surface charges involving the varied negative charges, positive charge and no charge. The chemical structures, morphologies and crystalline properties of four SNCs were investigated, together with the effect of surface charges to their cytotoxicity for two cell lines RAW267.4 and CAL27 by the cell proliferation and cell migration assay. The sulfuric acid-hydrolyzed SNC and phosphorylated SNC have more ordered regions and therefore display the higher crystallinities than the enzymatic treated SNC. Four obtained SNCs all exhibited weak cytotoxicity, indicating their good biocompatibility in the potential biomedical application.

Towards a better understanding of thermally treated polycarbophil matrix tablets for controlled release

Polycarbophil (POL), a polyacrylic acid cross-linked with divinyl glycol, is widely used in semisolid and solid dosage forms. When undergoing a thermal treatment in the range 120–160 °C, POL shows interesting morphological modifications, related to changes in physical properties, such as swelling of the powder granules, or hardening and matrix formation if included in the composition of a tablet. Thermal analysis conducted on POL highlighted a thermal event (Z) that can be correlated both to the shrinking of the powder granules and to the matrix formation in compacted POL powder. Modulated differential scanning calorimetry (MDSC) allowed to distinguish, inside event Z, an irreversible process overlapping with a reversible glass transition, attributable to the volatilization of residual solvents identified, through a complex TGA-FTIR-GC–MS interface, as acetate esters used for the polymer production as very fine powder. A specific interaction between acetates and POL, capable of stabilizing the polymer chains in a given conformation, was highlighted. The molecular rearrangement of the POL chains, following the volatilization of the solvent-stabilizers, is therefore ascribable to a loss of energetic stability of this material, which justifies the shrinking phenomena in the granules of the powder and the matrix formation when POL is compacted.

Cellulose nanocrystals in cancer diagnostics and treatment

Cancer is currently a major threat to public health, being among the principal causes of death to the global population. With carcinogenesis mechanisms, cancer invasion, and metastasis remaining blurred, cancer diagnosis and novel drug delivery approaches should be developed urgently to enable management and treatment. A dream break-through would be a non-invasive instantaneous monitoring of cancer initiation and progression to fast-track diagnosis for timely specialist treatment decisions. These innovations would enhance the established treatment protocols, unlimited by evasive biological complexities during tumorigenesis. It is therefore contingent that emerging and future scientific technologies be equally biased towards such innovations by exploiting the apparent properties of new developments and materials especially nanomaterials. CNCs as nanomaterials have undisputable physical and excellent biological properties that enhanced their interest as biomedical materials. This article therefore highlights CNCs utility in cancer diagnosis and therapy. Their extraction, properties, modification, in-vivo/in-vitro medical applications, biocompatibility, challenges and future perspectives are precisely discussed.