Nanocellulose/nanocarbon composites are newly emerging smart hybrid materials containing cellulose nanoparticles, such as nanofibrils and nanocrystals, and carbon nanoparticles, such as “classical” carbon allotropes (fullerenes, graphene, nanotubes and nanodiamonds), or other carbon nanostructures (carbon nanofibers, carbon quantum dots, activated carbon and carbon black). The nanocellulose component acts as a dispersing agent and homogeneously distributes the carbon nanoparticles in an aqueous environment. Nanocellulose/nanocarbon composites can be prepared with many advantageous properties, such as high mechanical strength, flexibility, stretchability, tunable thermal and electrical conductivity, tunable optical transparency, photodynamic and photothermal activity, nanoporous character and high adsorption capacity. They are therefore promising for a wide range of industrial applications, such as energy generation, storage and conversion, water purification, food packaging, construction of fire retardants and shape memory devices. They also hold great promise for biomedical applications, such as radical scavenging, photodynamic and photothermal therapy of tumors and microbial infections, drug delivery, biosensorics, isolation of various biomolecules, electrical stimulation of damaged tissues (e.g., cardiac, neural), neural and bone tissue engineering, engineering of blood vessels and advanced wound dressing, e.g., with antimicrobial and antitumor activity. However, the potential cytotoxicity and immunogenicity of the composites and their components must also be taken into account.

(1) Background: Decellularized xenogeneic tissues are promising matrices for developing tissue-engineered cardiovascular grafts. In vitro recellularization of these tissues with stromal cells can provide a better in vivo remodelling and a lower thrombogenicity of the graft. The process of recellularization can be accelerated using a cultivation bioreactor simulating physiological conditions and stimuli. (2) Methods: Porcine pericardium was decellularized using a custom-built decellularization system with an optimized protocol. Autologous porcine adipose-derived stromal cells (PrASCs), isolated from the subcutaneous fat tissue, were used for recellularizing the decellularized pericardium. A custom cultivation bioreactor allowing the fixing of the decellularized tissue into a special cultivation chamber was created. The bioreactor maintained micro-perfusion and pulsatile pressure stimulation in order to promote the ingrowth of PrASCs inside the tissue and their differentiation. (3) Results: The dynamic cultivation promoted the ingrowth of cells into the decellularized tissue. Under static conditions, the cells penetrated only to the depth of 50 µm, whereas under dynamic conditions, the tissue was colonized up to 250 µm. The dynamic cultivation also supported the cell differentiation towards smooth muscle cells (SMCs). In order to ensure homogeneous cell colonization of the decellularized matrices, the bioreactor was designed to allow seeding of the cells from both sides of the tissue prior to the stimulation. In this case, the decellularized tissue was recolonized with cells within 5 days of dynamic cultivation. (4) Conclusions: Our newly designed dynamic bioreactor markedly accelerated the colonization of decellularized pericardium with ASCs and cell differentiation towards the SMC phenotype.

We describe three new genera and four new species of the Histeridae (Coleoptera) from the mid-Cretaceous amber in Myanmar. Platycretus muscularis Simon Pražák & Lackner gen. & sp. nov. represents the first known fossil of the subfamily Histerinae from the Cretaceous. We assign the remaining three fossils, Olexum complanatum Simon Pražák & Lackner gen. & sp. nov., Cretanapleus seideli Simon Pražák & Lackner gen. & sp. nov., and Yethiha pubescens Simon Pražák & Lackner sp. nov. to the subfamily Dendrophilinae. Platycretus muscularis and O. complanatum have adaptations typical for the subcortical lifestyle (flattened body shape, dilated protibiae), proving this life strategy existed in independent lineages of clown beetles already in the Cretaceous. We also provide a review of all Histeridae fossil species described up to date and test the phylogenetic position of all of them including the newly described ones.

A larva of Cleroidea in Burmese amber is described, which is the first record of an immature beetle of the basal cucujiform superfamily for the Mesozoic. Well-preserved unique specimen is described and illustrated using traditional methods as well as synchrotron-radiation-based micro-computed tomography (SRµCT) to reconstruct the specimen and discern integumental details of cephalic structures, especially the mouthparts. Cretorhadalus constantinigen. et sp. nov. is unambiguously assigned to the melyrid lineage of Cleroidea and tentatively classified within the basal family Rhadalidae. Within this family, this fossil larva has the ancestral cleroid pattern of the stemmata (2+3) and well-developed hooked urogomphi. Based on a comparison with extant rhadalids, as well as most members of the melyrid lineage, the larvae and adults of this new species were probably carnivorous, living on the trunks and branches of trees or in galleries where they foraged for soft xylophagous insects.

Species in the beetle family Histeridae exhibit numerous defensive adaptations, from a generally compact and spheroid body shape to retractable tarsi, legs, heads, and antennae. Modes of antennal concealment are particularly variable, underscoring the importance of protecting these essential sensory structures. Understanding the evolution of these morphological features has been hindered by a weak understanding of the family’s basal phylogeny, and corresponding patterns of niche-use and morphological evolution. Cretaceous amber fossils have been proliferating, filling in important morphological gaps right around the time of the family’s explosive radiation. Here we describe 10 new species from Cretaceous Burmese ambers, six of them representing new genera: Palaeabraeus glabrus gen. nov. et sp. nov. (Abraeinae); Pseudacritus extinctus gen. nov. et sp. nov. (Abraeinae); Miculissima excavata gen. nov. et sp. nov. (unplaced to subfamily); Placatister cascus gen. nov. et sp. nov. (unplaced to subfamily); Cretomalus tibiodentatus gen. nov. et sp. nov. (Dendrophilinae: Paromalini); Prodigister tricostatus gen. nov. et sp. nov. (unplaced to subfamily); Anapleus punctulatus sp. nov. (Dendrophilinae: Anapleini); Pantostictus hirsutus sp. nov. (Abraeinae: Pantostictini); Phasmister kraliceki sp. nov. (Onthophilinae); and Phasmister planatus sp. nov. (Onthophilinae). A revised phylogenetic analysis that includes these taxa supports previous hints that inquilinous forms were prevalent and diverse during the Cretaceous. These results also support the contention that pressures in these environments to protect the critically important sensory apparatus, the antenna, were strong, driving multiple origins of two of the more protective configurations among extant taxa. Some of the new genera remain unplaced to subfamily, underscoring the gaps that still remain in the early fossil record for the family, and the continued need for more comprehensive analyses of combined data from extant taxa, along with additional extinct forms that we may assume will continue to be discovered.